LU.  S.  DEPARTMENT  OF 
AGRICULTUREj 

FARMERS'  BULLETIN  No. 


SEWAGE 
SEWERAGE 


HOMES 


if 


Rec'd  UCB  ENVi 

MAY  271986 


DISPOSAL  OF  FARM  SEWAGE  in  a  clean  man- 
ner is  always  an  important  problem.  The  aims 
of  this  bulletin  are  twofold:  (1)  To  emphasize  basic 
principles  of  sanitation;  (2)  to  give  directions  for 
constructing  and  operating  home  sewerage  works 
that  shall  be  simple,  serviceable,  and  safe. 

Care  in  operating  is  absolutely  necessary.  No  in- 
stallation will  run  itself.  Continued  neglect  ends  in 
failure  of  even  the  best  designed,  best  built  plants. 
If  the  householder  is  to  build  and  neglect,  he  might 
as  well  save  expense  and  continue  the  earlier  practice. 


Washington,  D.  C.  Issued  January,  1922 


SEWAGE  AND  SEWERAGE  OF  FARM 
HOMES. 


GEOEGE  M.  WAEREN, 
Hydraulic  Engineer,  Bureau  of  Public  Roads. 


Introduction 


CONTENTS. 
Page. 


o 

Plans  and  advice 


Sewage,    sewers,    and    sewerag 


fined. 


Nature  and  quantity  of  sewage 4 

Sewage -borne     diseases     and     their 


avoidance- 


Page. 


How  sewage  decomposes 9 

Importance    of   air   in    treatment   of 

10 
11 

_. 90 

Grease  traps ~         ~3 

General  procedure  


sewage 
Practical  utilities. 
Septic  tanks  .. 


INTRODUCTION. 

The  main  purpose  of  home-sewerage  works  is  to  get  rid  of 

m  such  way  as   (1)  to  ^  against  the  transmission  of  e 

germs  through  drinking  water,  flies,  or  other  means;  (2)  to  avoid 

creating  nuisance.    What  is  the  best  method  and  what  the  best  outfit 

are  questions  not  to  be  answered  offhand  from  afar.    A  treatment 

t  is  a  success  m  one  location  may  be  a  failure  in  another.     In 

every  instance  decision  should  be  based  upon  field  data  and  full 

knowledge  of  the  local  needs  and  conditions.   An  installation  planned 

from  assumed  Conditions  may  work  harm.    The  householder  may  be 

misled  as  to  the  purification  and  rely  on  a  protection  that  is  not  real 

P  °r  M  °d°r  and  find  a  nuisance  has  been 


PLANS  AND  ADVICE. 

Though  specific  plans  can  not  be  sent  in  the  absence  of  definite  in- 

formation and  though  plans  and  specifications  can  not  be  prepared 

e>  meet  individual  requirements,  the  Division  of  Agricultural  Engi- 

neering Bureau  of  Public  Roads,  gladly  gives  such  help  as  is  pos- 

b  e.    To  those  who  contemplate  installing  sewerage  works  on  farms 

1  who  furnish  the  information  outlined  under  the  caption  "Field 

ta,    on  page  52,  plans,  advice,  or  suggestions  will  be  sent.    Local 

•equirements  are  frequently  met  or  approximated  by  one  of  the  de- 

i  hand;  working  drawings  in  the  form  of  blue  prints  will  then 


4  Farmers'  Bulletin  1227. 

be  furnished.  Sometimes  the  designs,  slightly  modified,  may  suit  the 
needs.  In  other  instances  it  is  sufficient  to  send  published  bulletins 
or  give  written  suggestions  of  a  practical  nature. 

SEWAGE,  SEWERS,  AND  SEWERAGE  DEFINED. 

Human  excrements  (feces  and  urine)  as  found  in  closets  and  privy 
vaults  are  known  as  night  soil.  These  wastes  may  be  flushed  away 
with  running  water,  and  there  may  be  added  the  discharges  from 
washbasins,  bathtubs,  kitchen  and  slop  sinks,  laundry  trays,  washing 
vats,  and  floor  drains.  This  refuse  liquid  product  is  sewage,  and  the 
underground  pipe  which  conveys  it  is  a  sewer.  Since  sewers  carry 
foul  matter  they  should  be  water-tight,  and  this  feature  of  their 
construction  distinguishes  them  from  drains  removing  relatively 
pure  surface  or  ground  water.  Sewerage  refers  to  a  system  of 
sewers,  including  the  pipes,  tanks,  disposal  works,  and  appur- 
tenances. 

NATURE  AND  QUANTITY  OF  SEWAGE. 

Under  average  conditions  a  man  discharges  daily  about  3J  ounces 
of  moist  feces  and  40  ounces  of  urine,  the  total  in  a  year  approximat- 
ing 992  pounds.1  Feces  consist  largely  of  water  and  undigested  or 
partially  digested  food ;  by  weight  it  is  77.2  per  cent  water.2  Urine 
is  about  96.3  per  cent  water.2 

The  excrements  constitute  but  a  small  part  of  ordinary  sewage. 
In  addition  to  the  excrements  and  the  daily  water  consumption  of 
perhaps  40  gallons  per  person  are  many  substances  entering  into 
the  economy  of  the  household,  such  as  grease,  fats,  milk,  bits  of  food, 
meat,  fruit,  and  vegetables,  tea  and  coffee  grounds,  paper,  etc.  This 
complex  product  contains  mineral,  vegetable,  and  animal  substances, 
both  dissolved  and  undissolved.  It  contains  dead  organic  matter 
and  living  organisms  in  the  form  of  exceedingly  minute  vegetative 
cells  (bacteria)  and  animal  cells  (protozoa).  These  low  forms  of 
life  are  the  active  agents  in  destroying  dead  organic  matter. 

The  bacteria  are  numbered  in  billions  and  include  many  species, 
some  useful  and  others  harmful.  They  may  be  termed  tiny  scaven- 
gers, which  under  favorable  conditions  multiply  with  great  rapidity, 
their  useful  work  being  the  oxidizing  and  nitrifying  of  dissolved 
organic  matter  and  the  breaking  down  of  complex  organic  solids  to 
liquids  and  gases.  Among  the  myriads  of  bacteria  are  many  of  a 
virulent  nature.  These  at  any  time  may  include  species  which  are 
the  cause  of  well-known  infections  and  parasitic  diseases. 

*  Practical  Physiological  Chemistry,  by  Philip  B.  Hawk,  1916,  pp,  221,  359, 
9  Agriculture,  by  F.  H.  Storer,  1894,  vol.  2,  p,  70, 


Sewage  and  Sewerage  of  Farm  Homes.  5 

SEWAGE-BORNE  DISEASES  AND  THEIR  AVOIDANCE. 

Any  spittoon,  slop  pail,  sink  drain,  urinal,  privy,  cesspool,  sewage 
tank,  or  sewage  distribution  field  is  a  potential  danger.  A  bit  of 
spit,  urine,  or  feces  the  size  of  a  pin  head  may  contain  many  hundred 
germs,  all  invisible  to  the  naked  eye  and  each  one  capable  of  produc- 
ing disease.  These  discharges  should  be  kept  away  from  the  food 
and  drink  of  man  and  animals.  From  specific  germs  that  may  be 
carried  in  sewage  at  any  time  there  may  result  typhoid  fever,  tuber- 
culosis, cholera,  dysentery,  diarrhea,  and  other  dangerous  ailments, 
and  it  is  probable  that  other  maladies  may  be  traced  to  human  waste. 
From  certain  animal  parasites  or  their  eggs  that  may  be  carried  in 
sewage  there  may  result  intestinal  worms,  of  which  the  more  common 
are  the  hookworm,  roundworm,  whipworm,  eelworm,  tapeworm,  and 
seat  worm. 

Sewage,  drainage,  or  other  impure  water  may  contain  also  the 
causative  agents  of  numerous  ailments  common  to  live  stock,  such 
as  tuberculosis,  foot-and-mouth  disease,  hog  cholera,  anthrax,  gland- 
ers, and  stomach  and  intestinal  worms. 

Disease  germs  are  carried  by  many  agencies  and  unsuspectingly 
received  by  devious  routes  into  the  human  body.  Infection  may 
come  from  the  swirling  dust  of  the  railway  roadbed,  from  contact 
with  transitory  or  chronic  carriers  of  disease,  from  green  truck 
grown  in  gardens  fertilized  with  night  soil  or  sewage,  from  food 
prepared  or  touched  by  unclean  hands  or  visited  by  flies  or  vermin, 
from  milk  handled  by  sick  or  careless  dairymen,  from  milk  cans  and 
utensils  washed  with  contaminated  water,  or  from  cisterns,  wells, 
springs,  reservoirs,  irrigation  ditches,  brooks,  or  lakes  receiving  the 
surface  wash  or  the  underground  drainage  from  sewage-polluted  soil. 

Many  recorded  examples  show  with  certainty  how  typhoid  fever 
and  other  diseases  have  been  transmitted.  A  few  indicating  the 
responsibilities  and  duties  of  people  who  live  in  the  country  are 
cited  here. 

In  August,  1889,  a  sister  and  two  brothers  aged  18,  21,  and  23 
years,  respectively,  and  all  apparently  in  robust  health  dwelt  tp- 

f ether  in  a  rural  village  in  Columbiana  County,  Ohio.     Typhoid 
Bver  in  particularly  virulent  form  developed  after  use  of  drinking 
water  from  a  badly  polluted  surface  source.    The  deaths  of  all  three 
occurred  within  a  space  of  10  days. 

In  September  and  October,  1899,  63  cases  of  typhoid  fever,  result- 
ing in  5  deaths,  occurred  at  the  Northampton  (Mass.)  insane  hos- 
pital. This  epidemic  was  conclusively  traced  to  celery,  which  was 
eaten  freely  in  August  and  was  grown  and  banked  in  a  plot  that 
had  been  fertilized  in  the  late  winter  or  early  spring  with  the  solid 
residue  and  scrapings  from  a  sewage  filter  bed  situated  on  the 
hospital  grounds. 


6  Farmers'  Bulletin  1227. 

Some  years  ago  Dr.  W.  AV.  Skinner,  Bureau  of  Chemistry,  Depart- 
ment of  Agriculture,  investigated  the  cause  of  an  outbreak  of  typhoid 
fever  in  southwest  Virginia.  A  small  stream  meandered  through  a 
narrow  valley  in  which  five  10-inch  wells  about  450  feet  deep  had 
been  drilled  in  limestone  formation.  The  wells  were  from  50  to  400 
feet  from  the  stream,  from  which,  it  was  suspected,  pollution  was 
reaching  the  wells.  In  a  pool  in  the  stream  bed  approximately  one- 
fourth  mile  above  the  wells  several  hundred  pounds  of  common  salt 
were  dissolved.  Four  of  the  wells  were  cut  off  from  the  pump  and 
the  fifth  was  subjected  to  heavy  pumping.  The  water  discharged 
by  the  pump  was  examined  at  15-minute  intervals  and  its  salt  con- 
tent determined  over  a  considerable  period  of  time.  After  the  lapse 
of  several  15-minute  intervals  the  salt  began  to  rise  a^nd  continued  to 
rise  until  the  maximum  was  approximately  seven  times  that  at  the 
beginning  of  the  test,  thus  proving  the  facility  with  which  pollution 
may  pass  a  long  distance  underground  and  reach  deep  wells. - 

Probably  no  epidemic  in  American  history  better  illustrates  the 
dire  results  that  may  follow7  one  thoughtless  act  than  the  outbreak  of 
typhoid  fever  at  Plymouth,  Pa.,  in  1885.  In  January  and  February 
of  that  year  the  night  discharges  of  one  typhoid  fever  patient  were 
thrown  out  upon  the  snow  near  his  home.  These,  carried  by  spring 
thaws  into  the  public  water  supply,  caused  an  epidemic  running  from 
April  to  September.  In  a  total  population  of  about  8,000,  1}104  per- 
sons were  attacked  by  the  disease  and  114  died. 

Like  plants  and  animals,  disease  germs  vary  in  their  powers  of 
resistance.  Some  are  hardy,  others  succumb  easily.  Outside  the 
body  most  of  them  probably  die  in  a  few  days  or  weeks.  It  is  never 
certain  when  such  germs  may  not  lodge  where  the  immediate  sur- 
roundings are  favorable  to  their  life  and  reproduction.  Milk  is  one 
of  the  common  substances  in  which  germs  multiply  rapidly.  The 
experience  at  Northampton  shows  that  typhoid-fever  germs  may 
survive,  several  months  in  garden  soil.  Laboratory  tests  by  the 
United  States  Public  Health  Service  showed  that  typhoid- fever 
germs  had  not  all  succumbed  after  being  frozen  in  cream  74  days. 
(Public  Health  Reports,  Feb.  8,  1918,  pp.  163-166.)  Ravenel  kept 
the  spores  of  anthrax  immersed  for  244  days  in  the  strongest  tanning 
fluids  without  perceptible  change  in  their  vitality  or  virulence. 
(Annual  Report,  State  Department  of  Health,  Mass.,  1916,  p.  494.) 

Unsafe  practices. — Upon  thousands  of  small  farms  there  are  no 
privies  and  excretions  are  deposited  carelessly  about  the  premises. 
A  place  of  this  character  is  shown  in  figure  1.  Upon  thousands  of 
other  farms  the  privy  is  so  filthy  and  neglected  that  hired  men  and 
visitors  seek  near-by  sheds,  fields,  and  woods.  A  privy  of  this  char- 
acter is  shown  in  figure  2.  These  practices  and  conditions  exist  in 
every  section  of  the  country.  They  should  be  abolished. 

Deserving  of  severe  censure  is  the  old  custom  of  conveying  excre- 
ments or  sewage  into  abandoned  wells  or  some  convenient  stream. 
Such  a  practice  is  indecent  and  unsafe.  It  is  unnecessary  arid  is 
contrary  to  the  laws  of  most  of  the  States. 


Sewage  and  Sewerage  of  Farm  Homes.  7 

Likewise  dangerous  and  even  more  disgusting  is  the  old  custom  of 
using  human  excrement  or  sewage  for  the  fertilization  of  truck  land. 
Under  no  circumstances  should  such  wastes  be  used  on  land  devoted 
to  celery,  lettuce,  radishes,  cucumbers,  cabbages,  tomatoes,  melons, 
or  other  vegetables,  berries,  or  low-growing  fruits  that  are  eaten  raw. 
Disease  germs  or  particles  of  soil  containing  such  germs  may  adhere 
to  the  skins  of  vegetables  or  fruits  and  infect  the  eater. 

Upon  farms  it  is  necessary  to  dispose  of  excretal  wastes  at  no  great 
distance  from  the  dwelling.  The  ability  and  likelihood  of  flies 
carrying  disease  germs  direct  to  the  dinner  table,  kitchen,  or  pantry 
are  well  known.  Vermin,  household  pets,  poultry,  and  live  stock  may 
spread  such  germs.  For  these  reasons,  and  also  on  the  score  of  odor, 
farm  sewage  never  should  be  exposed. 


FIG.  1. — One  of  many  farms  lacking  the  simplest  sanitary  convenience. 

Important  safety  measure. — The  farmer  can  do  no  other  one  thing 
so  vital  to  his  own  arid  the  public  health  as  to  make  sure  of  the  con- 
tinued purity  of  the  farm  water  supply.  Investigations  indicate 
that  about  three  out  of  four  shallow  wells  are  polluted  badly. 

Wells  and  springs  are  fed  by  ground  water,  which  is  merely  natu- 
ral drainage.  Drainage  water  usually  moves  with  the  slope  of  the 
land.  It  always  dissolves  part  of  the  mineral,  vegetable,  and  animal 
matter  of  the  ground  over  or  through  which  it  moves.  In  this  way 
impurities  are  carried  into  the  ground  water  and  may  reach  distant 
wells  or  springs. 

Th  3  great  safeguards  are  clean  ground  and  wide  separation  of  the 
well  from  probable  channels  of  impure  drainage  water.  It  is  not 


8 


Farmers'  Bulletin  1227. 


enough  that  a  well  or  spring  is  50  or  K>0  feet  from  a  source  of  filth 
or  that  it  is  on  higher  ground.  Given  porous  ground,  a  seamy  ledge, 
or  long-continued  pollution  of  one  plat  of  land,  the  zone  of  conjtami- 
nation  is  likely  to  extend  long  distances,  particularly  in  downhill 
directions  or  when  the  water  is  low  through  drought  or  heavy  pump- 
ing. Only  when  the  surface  of  the  water  in  a  well  or  spring  is  at  a 
t higher  level  at  all  times  than  any  near- 
by source  of  filth  is  there  assurance 
of  safety  from  impure  seepage.  Some 
of  the  foregoing  facts  are  shown  dia- 
grammatically  in  figure  3.  Figure  4 
is  typical  of  those  insanitary,  poorly 
drained  barnyards  that  are  almost  cer- 
tain to  work  injury  to  wells  situated 
in  or  near  them.  Figure  5  illustrates 
poor  relative  location  of  privy,  cess- 
pool, and  well.  Figure  6  is  a  typical 
example  of  a  nuisance.  Accumula- 
tions of  filth  result  in  objectionable 
odor  and  noxious  drainage. 

Sewage  or  impure  drainage  water 
should  never  be  discharged  into  or 
upon  ground  draining  toward  a  well, 
spring,  or  other  source  of  wrater  supply. 
Neither  should  such  wastes  be  dis- 
charged into  openings  in  rock,  an 
abandoned  well,  nor  a  hole,  cesspool, 
vault,  or  tank  so  located  that  pollu- 
tion can  escape  into  wrater-bearing 
earth  or  rock.  Whatever  the  system  of 
sewage  disposal,  it  should  be  entirely 
and  widely  separated  from  the  water 
supply.  Further  information  on  lo- 
cating and  constructing  wells  is  given 
in  Farmers'  Bulletin  941,  "  Water  Systems  for  Farm  Homes,"  copies 
of  which  may  be  had  upon  request  to  the  Division  of  Publications, 
Department  of  Agriculture. 

Enough  has  been  said  to  bring  home  to  the  reader  these  vital 
points : 

1.  Never  allow  the  farm  sewage  or  excrements,  even  in  minutest 
quantity,  to  reach  the  food  or  water  of  man  or  live  stock. 

2.  Never  expose  such  wastes  so  that  they  can  be  visited  by  flies  or 
other  carriers  of  disease  germs. 

3.  Never  use  such  wastes  to  fertilize  or  irrigate  vegetable  gar- 
dens. 


BPR-REI383 

FIG.  2. — The  rickety,  uncomfort- 
able, unspeakably  foul,  dangerous 
ground  privy.  Neglected  by  the 
owner,  shunned  by  the  hired  man, 
avoided  by  the  guest,  who,  in 
preference,  goes  to  near-by  fields 
or  woods,  polluter  of  wells,  meet- 
Ing  place  of  house  flies  and  disease 
germs,  privies  of  this  character 
abide  only  because  of  man's  in- 
difference. 


Sewage  and  Sewerage  of  Farm  Homes.  9 

4.  Never  discharge  or  throw  such  wastes  into  a  stream,  pond,  or 
abandonee!  well,  nor  into  a  gutter,  ditch,  or  tile  drainage  system, 
which  naturally  must  have  outlet  in  some  watercourse. 

HOW  SEWAGE  DECOMPOSES. 

When  a  bottle  of  fresh  sewage  is  kept  in  a  warm  room  changes 
occur  in  the  appearance  and  nature  of  the  liquid.  At  first  it  is  light 


1379 


FIG.  3. — How  an  apparently  good  well  may  draw  foul  drainage.  Arrows  show  direction 
of  ground  Wcater  movement.  A-A,  Usual  water  table  (surface  of  free  water  in  the 
ground)  ;  B-B,  water  table  lowered  by  drought  and  pumping  from  well  D  ;  C-C,  water 
table  further  lowered  by  drought  and  heavy  pumping ;  E-F,  level  line  from  surface  of 
sewage  in  cesspool.  Well  D  is  safe  until  the  water  table  is  lowered  to  E ;  further  lower- 
ing draws  drainage  from  the  cesspool  and,  with  the  water  table  at  C-C,  from  the  barn. 
The  location  of  well  G  renders  it  unsafe  always. 

in  appearance  and  its  odor  is  slight.    It  is  well  supplied  with  oxygen, 
since  this  gas  is  always  found  in  waters  exposed  to  the  atmosphere. 


BPR-RE    1385 


PIG.  4. — An  insanitary,  poorly  drained  barnyard.  (Board  of  Health,  Milwaukee.) 
Liquid  manure  or  other  foul  drainage  is  sure  to  leach  into  wells  situated  in  or  near 
barnyards  of  this  character. 

In  a  few  hours  the  solids  in  the  sewage  separate  mechanically  ac- 
cording to  their  relative  weights ;  sediment  collects  at  the  bottom,  and 

85868°— 24 2 


10 


Farmers'  Bulletin  1227. 


a  greasy  film  covers  the  surface.  In  a  day's  time  there  is  an  enormous 
development  of  bacteria,  which  obtain  their  food  supply  from  the 
dissolved  carbonaceous  and  nitrogenous  matter.  As  long  as  free 
oxygen  is  present  this  action  is  spoken  of  as  aerobic  decomposition. 
There  is  a  gradual  increase  in  the  amount  of  ammonia  and  a  de- 
crease of  free  oxygen,  the  latter  going  to  support  bacterial  life. 
When  the  ammonia  is  near  the  maximum  and  the  free  oxygen  is  ex- 
hausted the  sewage  is  said  to  be  stale.  Following  exhaustion  of  the 
oxygen  supply,  bacterial  life  continues  profuse,  but  it  gradually 
diminishes  as  a  result  of  reduction  of  its  food  supply  and  the  poison- 
ous effects  of  its  own  wastes.  In  the  absence  of  oxygen  the  bacterial 


BPR-RE  isse 


FIG.  5. — Poor  relative  locations  of  privy,  cesspool,  and  well.  (State  Department  of 
Health,  Massachusetts.)  Never  allow  privy,  cesspool,  or  sink  drainage  to  escape 
into  the  plot  of  ground  from  which  the  water  supply  is  taken. 

action  is  spoken  of  as  anaerobic  decomposition.  The  sewage  turns 
darker  and  becomes  more  offensive.  'Suspended  and  settled  organic 
substances  break  apart  or  liquefy  later,  and  various  foul-smelling 
gases  are  liberated.  Sewage  in  this  condition  is  known  as  septic 
and  the  putrefaction  that  has  taken  place  is  called  septicization.  The 
odor  eventually  disappears,  and  a  dark,  insoluble,  mosslike  sub- 
stance remains  as  a  deposit.  Complete  reduction  of  this  deposit  may 
require  many  years. 

IMPORTANCE  OF  AIR  IN  TREATMENT  OF  SEWAGE. 

Decomposition  of  organic  matter  by  bacterial  agency  is  not  a 
complete  method  of  treating  sewage,  as  will  be  shown  later  under 


Sewage  and  Sewerage  of  Farm  Homes. 


11 


"  Septic  tanks."  It  is  sufficient  to  observe  here  that  in  all  practical 
methods  of  treatment  aeration  plays  a  vital  part.  The  air  or  the 
sewage,  or  both,  must  be  in  a  finely  divided  state,  as  when  sewage 
percolates  through  the  interstices  of  a  porous,  air-filled  soil.  The 
principle  involved  was  clearly  stated  30  years  ago  by  Hiram  F.  Mills, 
a  member  of  the  Massachusetts  State  Board  of  Health.  In  discuss- 


BPR-RE   1387 

FIG.  6. — A  typical  nuisance.  (Board  of  Health,  Milwaukee.)  A  yard  like  this  is  an 
eyesore,  a  fire  menace,  a  breeding  place  for  mosquitoes  and  vermin,  a  refuge  for  rats 
and  mice,  a  source  of  noxious  odors  and  foul  drainage,  and  a  violation  of  every  sani- 
tation code. 

ing  the  intermittent  filtration  of  sewage  through  gravel  stones  too 
coarse  to  arrest  even  the  coarsest  particles  in  the  sewage  Mr.  Mills 
said:  "The  slow  movement  of  the  sewage  in  thin  films  over  the 
surface  of  the  stones,  with  air  in  contact,  caused  a  removal  for  some 
months  of  97  per  cent  of  the  organic  nitrogenous  matter,  as  well 
as  99  per  cent  of  the  bacteria." 

PRACTICAL  UTILITIES. 

Previous  discussion  has  dealt  largely  with  basic  principles  of 
sanitation.  The  construction  and  operation  of  simple  utilities  em- 
bodying some  of  these  principles  are  discussed  in  the  following  order : 
(1)  Privies  for  excrements  only;  (2)  works  for  handling  wastes 
where  a  supply  of  water  is  available  for  flushing. 


12 


Farmers'  Bulletin  1227. 


PIT   PRIVY. 

*, 

Figure  7  shows  a  portable  pit  privy  suitable  for  places  of  the 
character  of  that  shown  in  figure  1,  where  land  is  abundant  and 
cheap,  and  in  such  localities  has  proved  practical.  It  provides,  at 
minimum  cost  and  with  least  attention,  a  fixed  place  for  depositing 
excretions  where  the  filth  can  not  be  tracked  by  man,  spread  by 
animals,  reached  by  flies,  nor  washed  by  rain. 

The  privy  is  light  and  inexpensive  and  is  placed  over  a  pit  in  the 
ground.  When  the  pit  becomes  one-half  or  two-thirds  full  the  privy 
is  drawn  or  carried  to  a  new  location.  The  pit  should  be  shallow, 
preferably  not  over  2£  feet  in  depth,  and  never  should  be  located  in 


2"x4'-3'Long 


Prepared  Roofing 
/  "Boards 


~2"x4'-3'  Long 


l  'Boards 


6$ 8' 'Screened  Vent 


PERSPECTIVE 


FIG.  7. — Portable  pit  privy.  For  use  where  land  is  abundant  and  cheap,  but  unless 
handled  with  judgment  can  not  be  regarded  as  safe.  The  privy  is  mounted  on  run- 
ners for  convenience  in  moving  to  new  locations. 

wet  ground  or  rock  formation  or  where  the  surface  or  the  strata  slope 
toward  a  well,  spring,  or  other  source  of  domestic  water  supply.  Be- 
sides standing  on  lower  ground  the  pit  should  never  be  within  200 
feet  of  a  well  or  spring.  Since  dryness  in  the  pit  is  essential,  the 
ground  should  be  raised  slightly  and  10  or  12  inches  of  earth  should 
be  banked  and  compacted  against  all  sides  to  shed  rain  water.  The 
banking  also  serves  to  exclude  flies.  If  the  soil  is  sandy  or  gravelly, 
the  pit  should  be  lined  with  boards  or  pales  to  prevent  caving.  The 
privy  should  be  boarded  closely  and  should  be  provided  with  screened 
openings  for  ventilation  and  light.  The  screens  may  consist  of 
standard  galvanized  or  black  enameled  wire  cloth  having  14  squares 


Sewage  and  Sewerage  of  Farm  Homes.  13 

to  the  inch.  The  whole  seat  should  be  easily  removable  for  cleaning. 
A  little  loose  absorbent  soil  should  be  added  daily  to  the  accumu- 
lation in  the  pit,  and  when  a  pit  is  abandoned  it  should  be  filled 
immediately  with  dry  earth  mounded  to  shed  water. 

A  pit  privy  for  use  in  field  Avork,  consisting  of  a  framework  of 
| -inch  iron  pipe  for  corner  posts  connected  at  the  top  with  J-inch 
iron  rods  bent  at  the  ends  to  right  angles  and  hung  with  curtains  of 
unbleached  muslin,  is  described  in  Public  Health  Report  of  the 
United  States  Public  Health  Service.  July  26, 1918. 

A  pit  privy,  even  if  moved  often,  can  not  be  regarded  as  safe. 
The  danger  is  that  accumulations  of  waste  may  overtax  the  purify- 
ing capacity  of  the  soil  and  the  leachings  reach  wells  or  springs. 
Sloping  ground  is  not  a  guaranty  of  safety ;  the  great  safeguard  lies 
in  locating  the  privy  a  long  distance  from  the  water  supply  and  as 
far  below  it  as  possible. 

SANITARY  PRIVY. 

The  next  step  in  evolution  is  the  sanitary  privy.  Its  construction 
must  be  such  that  it  is  practically  impossible  for  filth  or  germs  to 
be  spread  above  ground,  to  escape  by  percolation  underground,  or  to 
be  accessible  to  flies,  vermin,  chickens,  or  animals.  Furthermore,  it 
must  be  cared  for  in  a  cleanly  manner,  else  it  ceases  to  be  sanitary. 
To  secure  these  desirable  ends  sanitarians  have  devised  numerous 
types  of  tight-receptacle  privy.  Considering  the  small  cost  and  the 
proved  value  of  some  of  these  types,  it  is  to  be  regretted  that  few 
are  seen  on  American  farms. 

The  container  for  a  sanitary  privy  may  be  small — for  example,  a 
galvanized-iron  pail  or  garbage  can,  to  be  removed  from  time  to 
time  by  hand ;  it  may  be  large,  as  a  barrel  or  a  metal  tank  mounted 
for  moving;  or  it  may  be  a  stationary  underground  metal  tank  or 
masonry  vault.  The  essential  requirement  in  the  receptacle  is  per- 
manent water-tightness  to  prevent  pollution  of  soils  and  wells. 
Wooden  pails  or  boxes,  which  warp  and  leak,  should  not  be  used. 
Where  a  vault  is  used  it  should  be  shallow  to  facilitate  emptying 
and  cleaning.  Moreover,  if  the  receptacle  should  leak  it  is  better 
that  the  escape  of  liquid  should  be  in  the  top  soil,  where  air  and  bac- 
terial life  are  most  abundant. 

Sanitary  privies  are  classified  according  to  the  method  used  in 
treating  the  excretions,  as  dry  earth,  chemical,  liquefying. 

DRY-EARTH  PRIVY. 

Pail  type. — A  very  serviceable  pail  privy  is  shown  in  figures  8  and  D. 
The  method  of  ventilation  is  an  adaptation  of  a  system  that  has 
proved  very  effective  in  barns  and  other  buildings  here  and  abroad. 


14 


Farmers'  Bulletin  1227. 


A  flue  with  a  clear  opening  of  16  square  inches  rises  from  the  rear 
of  the  seat  and  terminates  above  the  ridgepole  in  a  cowl  or  small 
roofed  housing.  Attached  to  this  flue  is  a  short  auxiliary  duct,  4  by 
15  inches,  for  removing  foul  air  from  the  top  of  the  privy.  In  its 
upper  portion  on  the  long  sides  the  cowl  is  open,  allowing  free 
movement  of  air  across  the  top  of  the  flue.  In  addition  the  long 
sides  of  the  cowl  are  open  below  next  to  the  roof.  These  two  open- 
ings, with  the  connecting  vertical  air  passages,  permit  free  upward 
movement  of  air  through  the  cowl,  as  indicated  by  the  arrows.  The 
combined  effect  is  to  create  draft  from  beneath  the  seat  and  from  the 
top  of  the  privy.  The  ventilating  flue  is  2  by  8  inches  at  the  seat 
and  4  by  4  inches  5  feet  above.  The  taper  slightly  increases  the 


Rebate  /"for  l/ent  Hue  - 


PERSPECTIVE  PERSPECTIVE   OF  FRAMING 

FIG.  8. — Pail  privy.     Well  constructed,  ventilated,  and  screened.     With  proper  care  is 
sanitary  and  unobjectionable. 

labor  of  making  the  flue,  but  permits  a  2-inch  reduction  in  the  length 
of  the  building. 

In  plan  the  privy  is  4  by  4J  feet.  The  sills  are  secured  to  durable 
posts  set  about  4  feet  in  the  ground.  The  boarding  is  tight,  and  all 
vents  and  windows  are  screened  to  exclude  insects.  The  screens  may 
be  the  same  as  for  pit  privies  or,  if  a  more  lasting  material  is  de- 
sired, bronze  or  copper  screening  of  14  squares  to  the  inch  may  be  used. 
The  entire  seat  is  hinged,  thus  permitting  removal  of  the  receptacle 
and  facilitating  cleaning  and  washing  the  underside  of  the  seat  and 
the  destruction  of  spiders  and  other  insects  which  thrive  in  dark,  un- 
clean places.  The  receptacle  is  a  heavy  galvanized-iron  garbage  can. 
Heavy  brown-paper  bags  for  lining  the  can  may  be  had  at  slight 
cost,  and  their  use  helps  to  keep  the  can  clean  and  facilitates  empty- 


Sewage  and  Sewerage  of  Farm  Homes. 


15 


0/-.P- 


16 


Farmers'  Bulletin  1227. 


ing.  Painting  with  black  asphaltum  serves  a  similar  purpose  and 
protects  the  can  from  rust.  If  the  contents  are  frozen,  a  little  heat 
releases  them.  Of  nonfreezing  mixtures  a  strong  brine  made  witlj 
common  salt  or  calcium  chloride  is  effective.  Two  and  one-half  to  3 
pounds  of  either  thoroughly  dissolved  in  a  gallon  of  water  lowers  the 
freezing  point  of  the  mixture  to  about  zero.  Denatured  alcohol  or 
wood  alcohol  in  a  25  per  cent  solution  has  a  like  low  freezing  point 
and  the  additional  merit  of  being  noncorrosive  of  metals.  The  can 
should  be  emptied  frequently  and  the  contents  completely  buried  in 
a  thin  layer  by  a  plow  or  in  a,  shalloAV  hand-dug  trench  at  a  point 
below  and  remote  from  wells  and  springs.  Wherever  intestinal  dis- 
ease exists  the  contents  of  the  can  should  be  destroyed  by  burning 

or  made  sterile  before  burial  by  boil- 
ing or  by  incorporation  with  a  strong 
chemical  disinfectant. 

A  privy  ventilated  in  the  manner 
before  described  is  shown  in  figure 
10.  The  cowl,  however,  is  open  on 
four  sides  instead  of  two  sides  as1 
shown  in  figures  8  and  9.  The  work- 
ing drawings  (fig.  8  and  9)  show  that 
the  construction  of  a  privy  of  the 
kind  is  not  difficult.  Figure  11  gives 
three  suggestions  whereby  a  privy  may 
be  conveniently  located  and  the  ap- 
proach screened  or  partially  hidden  by 
latticework,  vines,  or  shrubbery. 

Vault  type. — A  primitive  and  yet 
serviceable  three-seat  dry-earth  privy 
of  the  vault  type  is  shown  in  figure  12. 
This  privy  was  constructed  in  1817 
upon  a  farm  at  TV7estboro,  Mass.  The 
vault,  made  of  bricks,  was  6  feet  long  by  5  feet  wide,  and  the  bottom 
was  1  foot  below  the  surface  of  the  ground.  The  brickwork  was  laid  in 
mortar,  and  the  part  below  the  ground  surface  was  plastered  on  the  in- 
side. The  outside  of  the  vault  was  exposed  to  light  and  air  on  all 
four  sides.  Across  the  long  side  of  the  vault  in  the  rear  was  a  door 
swinging  upward  through  which  the  night  soil  was  removed  two  or 
three  times  a  year,  usually  in  the  spring,  summer,  and  fall,  and 
hauled  to  a  near-by  field,  where  it  was  deposited  in  a  furrow,  just 
ahead  of  the  plow. 

Especial  attention  is  called  to  the  shallowness  of  the  vault  and  the 
lightened  labor  of  cleaning  it  out.  The  swinging  door  at  the  rear 
facilitated  the  sprinkling  of  dry  soil  or  ashes  over  the  contents  of  the 
vault,  thus  avoiding  the  necessity  of  carrying  dirt  and  dust  into  the 


BPR-RE   1382 


FIG.  10. — A  well-ventilated  privy  in 
Montana. 


Sewage  and  Sewerage  of  Farm  Homes. 


building  and  dust  settling  upon  the  seat.  This  privy  was  in  use  for 
nearly  100  years  without  renewal  or  repairs.  When  last  seen  the 
original  seat,  which  always  was  kept  painted,  showed  no  signs  of 


11 


CD 


decay.  Modern  methods  would  call  for  a  concrete  vault  of  guar- 
anteed water-tightness,3  proper  ventilation  and  screening,  and  hing- 
ing the  seat. 

-  Directions  for  mixing  and  placing  concrete  to  secure  water-tightness  are  contained  in 
an  article  entitled   "  Securing  a  dry  cellar."  U.   S.   Department  of  Agriculture   Yearbook, 
1919  ;  published  also  as  Yearbook  Separate  No.  824,  and  obtainable  for  10  cents  from  Jhe 
Superintendent  of  Documents,  Government  Printing  Office,  Washington,  D.  C, 
85868°  —24 3 


18 


Farmers    Bulletin  1227. 


P 

inch 

that 


Working  drawings  for  a  very  convenient  well-built  two-seat  vault 
privy  are  reproduced  in  figures  13  and  14.  The  essential  features  are 
shown  in  sufficient  detail  to  require  little  explanation.  With  con- 
crete mixtures  of  1 :2 : 3  (1  volume  cement.  2  volumes  sand.  3  volumes 

stone)    for   the    vault    and 

1:2:4  for  the  posts  there 
will  be  required  a  total  of 
about  2  cubic  yards  of  con- 
crete4, taking  3^  barrels  of 
cement.  1  cubic  yard  of 
sand,  and  H  cubic  yards  of 
broken  stone  or  screened 
gravel.  The  stone  or 
gravel  should  not  exceed  1 
in  diameter,  except 
a  few  cobblestones 
may  be  embedded  where 
the  vault  wall  is  thickest, 
thus  effecting  a  slight  sav- 
ing of  materials. 

CHEMICAL  CLOSET. 

A  type  of  sanitary  privy 
in  which  the  excrements  are 
received  direct!}'  into  a 
water-tight  receptacle  con- 
taining chemical  disinfect- 
ant is  meeting  with  consid- 
able  favor  for  camps,  parks, 
rural  cottages,  schools-:, 
hotels,  and  railway  stations. 
These  chemical  closets,4  as 
they  are  called. -are  made 
in  different  forms  and  are 
known  by  various  trade 
names.  Tn  the  simplest 
form  a  sheet -metal  recepta- 
cle is  concealed  in  a  small 
metal  or  wooden  cabinet,  and  the  closet  is  operated  usually  in  much 
the  same  manner  as  the  ordinary  pail  privy.  These  closets  are  very 
simple  and  compact,  of  good  appearance,  and  easy  to  install  or  move 

4  Among  publications  on  chemical  closets  are  the  following  :  "  Chemical  Closets,"  Re- 
print No.  404  from  the  Public  Health  Reports,  U.  S.  Public  Health  Service,  June  29,  1917, 
pp.  1017-1020  :  "  The  Chemical  Closet,"  Engineering  Bulletin  No.  5,  Mich.  State  Board 
of  Health.  October,  1916:  Health  Bulletin,  Va.  Department  of  Health,  March,  1917,  pp. 
214-219. 


I3O4 


FIG.    12. — A   primitive  vault    privy   in    Massachu 

setts.  Note  the  tight,  shallow,  easily  cleaned 
vault.  A,  Brick  vault  ."»  by  <;  feet,  boltom  about 
1  foot  in  the  ground;  B,  watertight  plastering; 
C,  rowlock  course  of  brick  ;  D,  door  hinged  at 
top:  /•:.  door  button;  /•'.  thnx'-panc  window 
hinged  at  lop;  <i.  passageway. 


Sewage  and  Sewerage  of  Farm  Homes. 


19 


from  place  to  place.  In  another  type,  known  as  the  chemical  tank 
closet,  the  receptacle  is  a  steel  tank  fixed  in  position  underground  or 
in  a  basement.  The  tank  has  a  capacity  of  about  125  gallons  per 
seat,  is  provided  with  a  hand-operated  agitator  to  secure  thorough 
mixing  of  the  chemical  and  the  excretions,  and  the  contents  are 
bailed,  pumped,  or  drained  out  from  time  to  time. 


Chemical  closets,  like  every  form  of  privy,  should  be  well  installed, 
cleanly  operated,  and  frequently  emptied,  and  the  wastes  should  re- 
ceive safe  burial.  With  exception  of  frequency  of  empyting,  the 
same  can  be  said  of  chemical  tank  closets.  With  both  forms  of  closet 
thorough  ventilation  or  draft  is  essential,  and  this  is  obtained  usu- 


20 


Farmers'  Bulletin  1227. 


ally  by  connecting  the  closet  vent  pipe  to  a  chimney  flue  or  extend- 
ing it  well  above  the  ridgepole  of  the  building.  The  contents  of  the 
container  should  always  be  submerged  and  very  low  temperatures 
guarded  against. 


<    6 


As  to  the  germicidal  results  obtained  in  chemical  closets,  few  data 
are  available.  A  disinfecting  compound  may  not  sterilize  more 
than  a  thin  surface  layer  of  the  solid  matter  deposited.  Experi- 
ments by  Dr.  Alvah  H.  Doty  with  various  agents  recommended  and 


Sewage  and  Sewerage  of  Farm  Homes. 


21 


widely  used  for  the  bedside  sterilization  of  feces  showed  "  that  at 

the  end  of  20  hours  of  exposure  to  the  disinfectant  but  one-eighth 

of  an  inch  of  the  fecal  mass  was  disinfected."5 

Plainly,  then,  to  destroy  all  bacterial  and  parasitic 

life  in  chemical  closets  three  things  are  necessary : 

(1)  A  very  powerful  agent;  (2)  permeation  of  the 

fecal   mass   by   the    agent;    (3)    retention    of   its 

strength  and  potency  until  permeation  is  complete. 

The   compounds   or   mixtures   commonly   used   in 

chemical  closets  are  of  two  general  kinds:  First, 

those  in  which  some  coal-tar  product  or  other  oily 

disinfectant  is  used  to  destroy  germs  and  deodorize, 


1035 


PIG.  15. — Chemical 
closet.  A.,  Water- 
tight sheet -metal 
container;  B,  metal 
or  wooden  cabinet ; 

C,  wooden    or    com- 
position   seat    ring; 

D,  hinged  cover;  E, 
3   or    4    inch   venti- 
lating   flue    extend- 
ing 18  inches  above 
roof  or  to  a   chim- 
ney ;  F,  air  inlets. 


FIG.  1C. — Chemical  tank  closet.  A,  Tank,  2  feet  3 
inches  by  4  feet  2  inches,  ^-inch  iron,  seams 
welded,  capacity  125  gallons ;  B,.  14-inch  cov- 
ered opening  for  recharging  and  emptying  tank  ^ 
C,  12-inch  galvanized  sheet-metal  tube;  D,' 
4-inch  sheet-metal  ventilating-  pipe  extending 
above  ridge-pole  or  to  a  chimney ;  E,  agitator  or 
paddle. 


leaving  the  solids 
little  changed  in 
form;  second, 
those  of  the  caus- 
tic class  that  dis- 
solve the  solids, 
which,  if  of  sufficient  strength  and  permeating  every  portion,  should 
destroy  most  if  not  all  bacterial  life.  Not  infrequently  the  chemical 


e  Annual  Report,  Mass.  State  Board  of  Health,  1914,  p.  727. 


22  Farmers    Bulletin  1227. 

solution  is  intended  to  accomplish  disinfection,  deodorization,  and 
reduction  to  a  liquid  or  semiliquid  state. 

A  simple  type  of  chemical  closet  is  shown  in  figure  15,  and  the 
essential  features  are  indicated  in  the  notation.  These  closets  with 
vent  pipe  and  appurtenances,  ready  for  setting  up,  retail  for  $20 
and  upward.  A  chemical  tank  closet,  retailing  for  about  $80  per 
seat,  is  shown  in  figure  16. 

The  Department  of  Agriculture  -occasionally  receives  complaints 
from  people  who  have  installed  chemical  closets,  usually  on  the 
score  of  odors  or  the  cost  of  chemicals. 

LIQUEFYING  CLOSET. 

Another  type  of  sanitary  privy,  known  as  a  liquefying  closet, 
makes  use  of  bacterial  action  as  an  aid  to  disposal.  The  excretions 
are  deposited  in  a  tight  receptacle  containing  water,  where  fermen- 
tation and  decomposition  reduce  a  large  part  of  the  organic  solids  to 
liquid  and  gaseous  forms.  Much  of  the  liquid  evaporates  and  the 
gases  diffuse,  so  that  the  volume  of  sewage  is  reduced  materially. 
More  or  less  insoluble  and  undigested  residue,  known  as  sludge,  grad- 
ually accumulates  at  the  bottom  of  the  receptacle,  which  from  time 
to  time  must  be  cleaned  out.  Disposal  of  the  partially  clarified  liquid 
and  the  sludge,  however,  involves  much  less  labor  than  would  be 
needed  to  handle  the  untreated  excrements. 

Liquefying  closets  have  been  used  many  years  with  fair  satisfac- 
tion. The  receptacle  sometimes  is  a  tight  brick  vault,  but  more  fre- 
quently a  barrel  or  hogshead  with  one  end  nearly  flush  with  the 
ground.  Over  this  is  mounted  the  seat,  sometimes  with  iron  bars 
beneath  to  prevent  accident  to  small  children,  and  the  whole  is  in- 
closed in  a  small  frame  house.  The  vault  usually  is  bailed  or  pumped 
out  two  or  three  times  a  year. 

Upon  farms  where  slope,  soil,  and  drainage  conditions  are  favor- 
able the  effluent  from  liquefying  closets  may  be  distributed  and 
aerated  by  means  of  drain  tile  laid  in  the  top  soil  or  in  shallow  beds 
filled  with  cinders,  coke,  gravel,  or  stone.  Figure  17  shows  a  simple 
one-chamber  liquefying  closet  with  shallow  distribution  of  the  efflu- 
ent in  a  stone-filled  trench.  The  vault  or  tank  consists  of  vitrified 
sewer  pipe,  a  simple  and  cheap  construction.  Where  a  larger  vault 
is  required  concrete  or  brick  may  be  used,  the  usual  capacity  being 
12  or  13  gallons  to  a  person. 

Faults  in  liquefying  closets  are  objectionable  odor,  clogging  of 
the  screen  over  the  outlet,  or  insufficient  water  in  the  vault  to  insure 
proper  bacterial  action.  A  ventilating  pipe  should  be  provided 
extending  from  beneath  the  seat  to  above  the  roof.  The  outlet  pipe 
should  not  be  less  than  4  inches  in  diameter,  and  the  mesh  of  the 
screen  should  not  be  less  than  one- fourth  inch.  The  contents  of 


Sewage  and  Sewerage  of  Farm  Homes. 


23 


Ill 

CrossSection  of  DistributionTile 

FIG.  17. — Liquefying  closet.  A,  Excavation  about  3  feet  3  inches  in  diameter ;  B,  3-foot 
length,  vitrified  Y  branch,  24  by  4  inches  ;  C,  2-foot  length  of  24-inch  hard  burned 
drain  tile  or  vitrified  sewer  pipe ;  D,  4  by  4  inch  Y  branch ;  E,  1-foot  length  of 
4-inch  cast-iron  soil  pipe  ;  F,  concrete  bottom  making  water-tight  seal ;  G,  joints  made 
water  tight  by  use  of  a  strand  of  jute  or  oakum  and  rich  Portland  cement  mortar  or 
hot  bituminous  jointing  compound  ;  II ',  submerged  outlet ;  /,  removable  strainer  with 
openings  \  inch  or  larger ;  J,  4-inch  removable  plug :  K,  4-inch  drain  tile  laid  on  good 
slope  in  trench  about  15  inches  deep,  ends  of  tile  butting,  joints  covered  with  strips 
of  tarred  paper  extending  three-fourths  of  the  way  around  the  tile;  L,  removable  seat 
supported  by  end  cleats  ;  M,  4  by  4  inch  ventilating  flue,  bottom  portion  removable ;  N, 
hinged  door  to  facilitate  bailing  out  sludge. 


24  Farmers'  Bulletin   1227.' 

the  vault  should  be  diluted  with  water  at  intervals,  depending  upon 
the  number  of  persons  using  the  closet  and  the  rapidity  of  evapora- 
tion. Dilution  may  be  effected  by  pouring  in  1  or  2  gallons  with  a 
pail,  or  a  small  pipe  may  be  led  from  the  eaves  trough  of  the  closet 
to  the  vault.  The  effluent  may  be  light  colored  and  apparently  in- 
offensive, but  it  still  is  sewage,  and  therefore  the  distributing  tile 
never  should  be  laid  in  the  vicinity  of  a  well  or  spring. 

DISINFECTANTS  AND  DEODORANTS. 

Disinfection  is  the  destruction  of  disease  germs.  Sterilization  is 
the  destruction  of  all  germs  or  bacteria,  both  the  harmful  and  the 
useful.  Antisepsis  is  the  checking  or  restraining  of  bacterial 
growth.  Deodorization  is  the  destruction  of  odor.  Unfortunately 
in  practice  none  of  these  processes  may  be  complete.  The  agent  may 
be  of  inferior  quality,  may  have  lost  its  potency,  or  may  not  reach 
all  parts  of  the  mass  treated.  A  disinfectant  or  germicide  is  an 
agent  capable  of  destroying  disease  germs ;  an  antiseptic  is  an  agent 
merely  capable  of  arresting  bacterial  growth,  and  it  may  be  a  dilute 
disinfectant ;  a  deodorant  is  an  agent  that  tends  to  destroy  odor,  but 
whose  action  may  consist  in  absorbing  odor  or  in  masking  the  origi- 
nal odor  with  another  more  agreeable  one.c 

Of  active  disinfecting  agents,  heat  from  fire,  live  steam,  or  boiling 
water  is  the  surest.  The  heat  generated  by  the  slaking  of  quick- 
lime has  proved  effective  with  small  quantities  of  excreta.  Results 
of  tests  by  the  Massachusetts  State  Board  of  Health7  show  that 
the  preferable  method  consists  in  adding  sufficient  hot  water  (120° 
to  140°  F.)  to  cover  the  excrement  in  the  receptacle,  then  adding 
small  pieces  of  fresh  strong  quicklime  in  amount  equal  to  about 
one-third  of  the  bulk  of  water  and  excrement  combined,  covering 
the  receptacle,  and  allowing  it  to  stand  H  hours  or  longer. 

Among  chemical  disinfectants  a  strong  solution  of  sodium  hydrox- 
ide (caustic  soda)  or  potassium  hydroxide  (caustic  potash,  lye)  is 
very  effective  and  is  useful  in  dissolving  grease  and  other  organic 
substances.  Both  chemicals  are  costly,  but  caustic  soda  is  less  ex- 
pensive than  caustic  potash  and  constitutes  most  of  the  ordinary 
commercial  lyes.  Chlorinated  lime  (chloride  of  lime,  bleaching 
powder)  either  in  solution  or  in  powdered  form  is  valuable.  For 
the  disinfection  of  stools  of  typhoid- fever  patients  the  Virginia 
State  Board  of  Health8  recommends  thoroughly  dissolving  | 
pound  of  best  chloride  of  lime  in  1  gallon  of  water  and  allowing 

6  Those  desiring  more  explicit  information  on  disinfectants  and  the  principles  of  disin- 
fection are  referred  to  U.  S.  Department  of  Agriculture  Farmers'  Bulletins  926,  "  fcome 
Common  Disinfectants,"  and  954,  "  The  Disinfection  of  Stablea,"  and  to  publications  of 
the  U.  S.  Public  Health  Service. 

'Annual  Report,  Mass.  State  Board  of  Health,  1014,  pp.  727-729. 

8  Health  Bulletin,  Va.  State  Board  of  Health,  Juno,  1917,  pp.  277-280. 


Sewage  and  Sewerage  of  Farm  Homes.  25 

the  solution  to  cover  the  feces  for  at  least  1  hour.  The  solution 
should  be  kept  in  well-stoppered  bottles  and  used  promptly,  cer- 
tainly within  2  or  3  days.  Copper  sulphate  (blue  vitriol,  bluestone) 
in  a  5  per  cent  solution  (1  pound  in  2-i-  gallons  of  water)  is  a  good 
but  rather  costly  disinfectant.  None  of  the  formulas  here  given 
is  to  be  construed  as  fixed  and  precise.  Conditions  may  vary  the 
proportions,  as  they  always  will  vary  the  results.  The  reader  should 
remember  that  few,  if  any,  chemical  disinfectants  can  be  expected 
fully  to  disinfect  or  sterilize  large  masses  of  excrement  unless  the 
agent  is  used  repeatedly  and  in  liberal  quantities  or  mechanical 
means  are  employed  to  secure  thorough  incorporation. 

Among  deodorants  some  of  the  drying  powders  mentioned  below 
possess  more  or  less  disinfecting  power.  Chloride  of  lime,  though 
giving  off  an  unpleasant  odor  of  chlorine,  is  employed  extensively. 
Lime  in  the  form  of  either  quicklime  or  milk  of  lime  (whitewash) 
is  much  used  and  is  an  active  disinfectant.  To  prepare  milk  of  lime 
a  small  quantity  of  water  is  slowly  added  to  good  fresh  quicklime 
in  lumps.  As  soon  as  the  quicklime  is  slaked  a  quantity  of  water, 
about  four  times  the  quantity  of  lime,  is  added  and  stirred  thor- 
oughly. When  used  as  a  whitewash  the  milk  of  lime  is  thinned  as 
desired  with  water  and  kept  well  stirred.  Liberal  use  of  milk  of 
lime  in  a  vault  or  cesspool,  though  it  may  not  disinfect  the  contents, 
is  of  use  in  checking  bacterial  growth  and  abating  odor.  To  give  the 
best  results  it  should  be  used  frequently,  beginning  when  the  vault  or 
cesspool  is  empty.  Iron  sulphate  (green  vitriol,  copperas)  because 
of  its  affinity  for  ammonia  and  sulphides  is  used  as  a  temporary 
deodorizer  in  vaults,  cesspools,  and  drains;  1  pound  dissolved  in  4 
gallons  of  water  makes  a  solution  of  suitable  strength. 

PREVENTION   OF  PRIVY   NUISANCE. 

The  following  is  a  summary  of  simple  measures  for  preventing  a 
privy  from  becoming  a  nuisance : 

1.  Locate    the    privy    inconspicuously    and    detached    from    the 
dwelling. 

2.  Make  the  receptacle  or  vault  small,  shallow,  easy  of  access,  and 
water-tight. 

3.  Clean  out  the  vault  often.     Do  not  wait  until  excrement  has 
accumulated   and   decomposition   is   sufficiently   advanced  to   cause 
strong  and  foul  odors. 

4.  Sprinkle  into  the  vault  daily  loose  dry  soil,  ashes,  lime,  sawdust, 
ground  gypsum  (land  plaster) ,  or  powdered  peat  or  charcoal.     These 
will  absorb  liquid  and  odor,  though  they  may  not  destroy  disease 
germs. 

5.  Make  the  privy  house  rain-proof;  ventilate  it  thoroughly,  and 
screen  all  openings. 

sr,sus°—  24 4 


26  Farmers'  Bulletin  1227. 

OBJECTION  TO  PRIVIES. 

All  the  methods  of  waste  disposal  heretofore  described  are  open  to 
the  following  objections : 

1.  They  do  not  take  care  of  kitchen  slops  and  liquid  wastes  inci- 
dent to  a  pressure  water  system. 

2.  They  retain  filth  for  a  considerable  period  of  time  with  proba- 
bility of  odors  and  liability  of  transmission  of  disease  germs. 

3.  They  require  more  personal  attention  and  care  than  people  gen- 
erally are  willing  to  give. 

By  far  the  most  satisfactory  method  yet  devised  of  caring  for 
sewage  calls  for  a  supply  of  water  and  the  flushing  away  of  all 
wastes  as  soon  as  created  through  a  water-tight  sewer  to  a  place 
where  they  undergo  treatment  and  final  disposal. 

KITCHEN-SINK  DRAINAGE. 

A  necessity  in  every  dwelling  is  effective  disposal  of  the  kitchen- 
sink  slops.  This  necessity  ordinarily  arises  long  before  the  farm 
home  is  supplied  with  water  under  pressure  and  the  conveniences 
that  go  with  it.  Hence  the  first  call  for  information  on  sewage  dis- 
posal is  likely  to  relate  merely  to  sink  drainage.  This  waste  water 
though  it  may  not  be  as  dangerous  to  health  as  sewage  containing 
human  excrements  is  still  a  menace  to  the  farm  well  and  capable  of 
creating  disagreeable  odor. 

The  usual  method  of  disposing  of  sink  slops  is  to  allow  them  to 
dribble  on  or  beneath  the  surface  of  the  ground  close  to  the  house. 
Such  drainage  should  be  taken  in  a  water-tight  carrier  at  least  100 
feet  downhill  from  the  well  and  discharged  below  the  surface  of  the 
ground.  Every  sink  should  be  provided  with  a  suitable  screen  to 
keep  all  large  particles  out  of  the  waste  pipe.  An  approved  form  of 
sink  strainer  consists  of  a  brass  plate  bolted  in  position  over  the  out- 
let and  having  at  least  37  perforations  not  larger  than  one-fourth 
inch  in  diameter.  Provided  a  sink  is  thus  equipped  and  is  given 
proper  care  and  the  land  has  fair  slope  and  drainage,  the  waste  water 
may  be  conducted  away  through  a  water-tight  sewer  and  distributed 
in  the  soil  by  means  of  a  short  blind  drain.  The  blind  drain  may  be 
conveniently  made  of  drain  tile  in  the  manner  shown  in  figure  17. 
A  simple  installation,  consisting  of  a  kitchen  sink  and  pump  and 
means  of  disposal  as  described,  is  shown  in  figure  18. 

CESSPOOLS. 

Where  farms  have  water  under  pressure  an  open  or  leaching  cess- 
pool is  a  common  method  of  disposing  of  the  sewage.  Ordinary 
cesspools  are  circular  excavations  in  the  ground,  lined  with  stone  or 
brick  laid  without  mortar.  They  vary  from  5  to  10  feet  in  diameter 
and  from  7  to  12  feet  in  depth.  Sometimes  the  top  is  arched  and 


Sewage  and  Sewerage  of  Farm  Homes. 


27 


capped  at  the  ground  surface  by  a  cover  of  wood,  stone,  or  cast  iron. 
At  other  times  the  walls  are  carried  straight  up  and  boards  or  planks 
are  laid  across  for  a  cover,  and  the  entire  structure  is  hidden  with  a 
hedge  or  shrubbery. 

Except  under  the  most  favorable  conditions  the  construction  and 
use  of  a  cesspool  can  not  be  condemned  too  strongly.  They  are  only 
permissible  where  no  other  arrangement  is  possible.  Leaching  cess- 
pools especially  are  open  to  these  serious  objections: 

1.  Unless  located  in  porous  soil,  stagnation  is  likely  to  occur, 
and  failure  of  the  liquid  to  seep  away  may  result  in  overflow  on 


FIG.  18. — How  to  waste  kitchen-sink  drainage.  A,  Sink  ;  B,  waste  pipe ;  C,  trap  ;  D,  clean- 
out  ;  E,  box  filled  with  hay,  straw,  sawdust,  excelsior,  coke,  or  other  insulating  ma- 
terial ;  F,  4-inch  vitrified  sewer-pipe,  hubs  uphill,  and  joints  made  water  tight  for  at 
least  100  feet  downhill  from  a  well ;  G,  4-inch  vitrified  sewer  pipe,  hubs  downhill, 
joints  slightly  open,  laid  in  an  18-inch  bed  of  coarse  sand,  gravel,  stone,  broken  brick, 
slag,  cinders,  or  coke ;  IT,  strip  of  tarred  paper  or  burlap  or  a  thin  layer  of  hay, 
straw,  cornstalks,  brush,  or  sods,  grass  side  down ;  I,  12  inches  of  natural  soil ;  J,  stone- 
filled  pit.  As  here  illustrated,  water  is  drawn  by  a  pitcher  or  kitchen  pump  (K) 
through  a  li  or  1|  inch  galvanized-iron  suction  pipe  (L)  from  a  cistern  (M).  The 
suction  pipe  should  be  laid  below  frost  and"  on  a  smooth  upward  grade  from  cistern 
to  pump  and  be  provided  with  a  foot  valve  (N)  to  keep  the  pump  primed.  If  a  foot 
valve  is  used,  pump  and  pipe  must  be  safe  from  frost  or  other  means  than  tripping 
the  pump  be  provided  for  draining  the  system. 

the  surface  of  the  ground  and  the  creation  of  a  nuisance  and  a 
menace. 

2.  They  retain  a  mass  of  filth  in  a  decomposing  condition  deep  in 
the  ground  where  it  is  but  slightly  affected  by  the  bacteria  and  air 
of  the  soil.  In  seeping  through  the  ground  it  may  be  strained,  but 
there  can  be  no  assurance  that  the  foul  liquid  with  little  improvement 
in  its  condition  may  not  pass  into  the  ground  water  and  pollute 
wells  and  springs  situated  long  distances  away  in  the  direction  of 
underground  flow. 

For  the  purpose  of  avoiding  soil  and  ground-water  pollution  cess- 
pools have  been  made  of  water-tight  construction  and  the  contents 


28  Farmers'  Bulletin  1227. 

removed  by  bailing  or  pumping.  Upon  the  fartn,  however,  this  type 
of  construction  has  little  to  recommend  it,  for  the  reason  that  facili- 
ties for  removing  and  disposing  of  the  contents  in  a  clean  manner  are 
lacking. 

In  some  instances  cesspools  have  been  made  water-tight,  the  out- 
flow being  effected  by  three  or  four  elbows  or  T-branches  set  in  the 
masonry  near  the  top,  with  the  inner  ends  turned  down  below  the 
water  surface,  the  whole  surrounded  to  a  thickness  of  several  feet 
with  stone  or  gravel  intended  to  act  as  a  filtering  medium.  Tests  of 
the  soil  water  adjacent  to  cesspools  of  this  type  show  that  no  reliance 
should  be  placed  upon  them  as  a  means  of  purifying  sewage,  the 
fatal  defects  being  constant,  saturation  with  sewage  and  lack  of  air 
supply.  To  the  extent  that  the  submerged  outlets  keep  back  grease 
and  solid  matters  the  scheme  is  of  service  in  preventing  clogging 
of  the  pores  of  the  surrounding  ground. 

Where  the  ground  about  a  cesspool  has  become  clogged  and  water- 
logged, relief  is  often  secured  by  laying  several  lines  of  drain 
tile  at  shallow  depth,  radiating  from  the  cesspool.  The  ends  of  the 
pipes  within  the  cesspool  should  turn  down,  and  it  is  advantageous 
to  surround  the  lines  of  pipe  with  stones  or  coarse  gravel,  as  shown 
in  figures  IT  and  18  and  discussed  under  "  Septic  tanks/'  In  this 
way  not  only  is  the  area  of  percolation  extended,  but"  aeration  and 
partial  purification  of  the  sewage  are  effected. 

Where  a  cesspool  is  located  at  a  distance  from  a  dwelling  and 
there  is  opportunity  to  lead  a  vent  pipe  up  the'  side  of  a  shed,  barn, 
or  any  stable  object  it  is  advisable  to  do  so  for  purposes  of  ven- 
tilation. Where  the  conditions  are  less  favorable  it  may  be  best, 
because  of  the  odor,  to  omit  any  direct  vent  pipe  from  the  cesspool 
and  rely  for  ventilation  on  the  house  sewer  and  main  soil  stack  ex- 
tending above  the  roof  of  the  house. 

Cesspools  should  be  emptied  and  cleaned  at  least  once  a  year  and 
the  contents  given  safe  burial  or.  with  the  requisite  permission, 
wasted  in  some  municipal  sewerage  system.  After  cleaning,  the 
walls  and  bottom  may  be  treated  with  a  disinfectant  or  a  deodorant. 

SEPTIC  TANKS. 

A  tight,  underground  septic  tank  with  shallow  distribution  of  the 
effluent  in  porous  soil  generally  is  the  safest  and  least  troublesome 
method  of  treating  sewage  upon  the  farm,  while  at  the  same  time 
more  or  less  of  the  irrigating  and  manurial  value  of  the  sewage  may 
be  realized. 

The  late  Prof.  Kinnicutt  used  to  say  that  a  septic  tank  is  "  simply 
a  cesspool,  regulated  and  controlled."  The  reactions  described  under 
the  captions  "  How  sewage  decomposes,"  "  Liquefying  closet,"  and 
"  Cesspools"  take  place  in  septic  tanks. 


Sewage  and  Sewerage  of  Farm  Homes.  29 

In  all  sewage  tanks,  whatever  their  size  and  shape,  a  portion  of 
the  solid  matter,  especially  if  the  sewage  contains  much  grease,  floats 
as  scum  on  the  liquid,  the  heavier  solids  settle  to  form  sludge,  while 
finely  divided  solids  and  matter  in  a  state  of  emulsion  are  held  in 
suspension.  If  the  sludge  is  retained  in  the  bottom  of  the  tank  and 
converted  or  partly  converted  into  liquids  and  gases  the  tank  is  called 
a  septic  tank  and  the  process  is  known  as  septicization.  The  process 
is  sometimes  spoken  of  as  one  of  digestion  or  rotting. 

History. — Prototypes  of  the  septic  tank  were  known  in  Europe 
nearly  50  years  ago.  Between  1876  and  1893  a  number  of  closed  tanks 
with  submerged  inlets  and  outlets  embodying  the  principle  of  storage 
of  sewage  and  liquefaction  of  the  solids  were  built  in  the  United  States 
and  Canada.  It  was  later  seen  that  many  of  the  early  claims  for  the 
septic  process  were  extravagant.  In  recent  years  septic  tanks  have 
been  used  mainly  in  small  installations,  or,  where  employed  in  large 
installations,  the  form  has  been  modified  to  secure  digestion  of  the 
sludge  in  a  separate  compartment,  thus  in  a  measure  obviating  dis- 
advantages that  exist  where  septicization  takes  place  in  the  presence 
of  the  entering  fresh  sewage. 

Purposes. — The  purposes  of  a  septic  tank  are  to  receive  all  the  farm 
sewage,  as  defined  on  page  4,  hold  it  in  a  quiet  state  for  a  time, 
thus  causing  partial  settlement  of  the  solids,  and  by  nature's  proc- 
esses of  decomposition  insure,  as  fully  as  may  be,  the  destruction  of 
the  organic  matter. 

Limitations. — That  a  septic  tank  is  a  complete  method  of  sewage 
treatment  is  a  widespread  but  wrong  impression.  A  septic  tank 
does  not  eliminate  odor  and  does  not  destroy  all  organic  solids.  On 
the  contrary,  foul  odors  develop,  and  of  all  the  suspended  matter  in 
the  sewage  about  one-third  escapes  with  the  effluent,  about  one-third 
remains  in  the  tank,  and  about  one-third  only  is  destroyed  or  reduced 
to  liquids  and  gases.  The  effluent  is  foul  and  dangerous.  It  may  con- 
tain even  more  bacteria  than  the  raw  sewage,  since  the  process  in- 
volves intensive  growths.  As  to  the  effects  upon  the  growth  and  viru- 
lence of  disease  germs  little  is  known  definitely.  It  is  not  believed 
that  such  germs  multiply  under  the  conditions  prevailing  in  a  septic 
tank.  If  disease  germs  are  present  many  of  their  number  along  with 
other  bacteria  may  pass  through  with  the  flow  or  may  be  enmeshed 
in  the  settling  solids  and  there  survive  a  long  time.  Hence  the  farmer 
should  safeguard  wells  and  springs  from  the  seepage  or  discharges 
from  a  septic  tank  as  carefully  as  from  those  of  liquefying  closets 
and  cesspools. 

Further  treatment  of  effluents. — The  effluent  of  a  septic  tank  or  any 
other  form  of  sewage  tank  is  foul  and  dangerous.  Whether  or  not 
the  solids  are  removed  by  screening,  by  short  periods  of  rest,  as  in 
plain  or  modified  forms  of  settling  tanks,  or  by  longer  quiescence, 


30  Farmers    Bulletin  1227. 

as  in  septic  tanks,  .the  effluent  generally  requires  further  treatment 
to  reduce  the  number  of  harmful  organisms  and  the  liability  of 
nuisance.  This  further  treatment  usually  consists  of  some  mode  of 
filtration.  In  the  earliest  example  of  such  treatment  the  sewage 
was  used  to  irrigate  land  by  either  broad  flooding  or  furrow  irriga- 
tion. By  another  method  the  sewage,  is  distributed  underground  by 
means  of  drain  tile  laid  with  open  joints,  as  illustrated  in  figures 
17,  29,  and  32. 

Artificial  sewage  filters  are  composed  of  coarse  sand,  screened 
gravel,  broken  stone,  coke,  or  other  material,  and  the  sewage  is 
applied  in  numerous  ways.  Since  filtration  is  essentially  an  oxidiz- 
ing process  requiring  air,  the  sewage  is  applied  intermittently  in 
doses.9 

If  properly  designed  and  operated,  filters  of  sand,  coke,  or  stone 
are  capable  of  excellent  results.  Under  the  most  favorable  condi- 
tions it  is  unwise  to  discharge  the  effluent  of  a  sewage  filter  in  the 
near  vicinity  of  a  source  of  water  supply.  Under  farm  conditions 
filters  are  usually  neglected  or  the  sewage  is  improperly  applied, 
resulting  in  the  clogging  and  befouling  of  sand  filters  and  the  dis- 
charge from  stone  filters  of  an  effluent  which  is  practically  as  danger- 
ous and  even  more  offensive  than  raw  sewage.  Moreover  unless  the 
filters  are  covered  there  are  likely  to  be  annoying  odors, 'and  there 
is  always  the  possibility  of  disease  germs  being  carried  by  flies  where 
sewage  is  exposed  in  the  vicinity  of  dwellings.  Hence  it  seems  more 
practical  for  the  farmer,  avoiding  the  expense  of  earth  embankments 
or  masonry  sides  and  bottom  for  a  filter  bed,  to  waste  the  tank 
effluent  beneath  the  surface  of  such  area  of  land  as  is  most  suitable 
and  available.  This  method  of  applying  sewage  to  the  soil  or  sub- 
soil is  often  spoken  of  as  subirrigation.  but  subsoil  distribution  of 
sewage  is  different  in  principle  and  practice  from  subirrigation  for 
the  increase  of  crop  yields.  Subirrigation  is  rarely  successful  unless 
the  land  is  nearly  level,  the  top  soil  porous  and  underlaid  with  an 
impervious  stratum  to  hold  the  water  within  reach  of  plant  roots, 
and  unless  a  relatively  large  quantity  of  water  is  used  and -the  work 
is  skillfully  done.  On  the  other  hand,  the  quantity  of  sewage  on 
farms  being  small,  it  may  be  wasted  in  hilly  ground,  which  should  be 
as  porous,  deeply  drained,  and  dry  as  possible. 

Parts  of  a  system. — The  four  parts  of  a  septic-tank  installation  with 
subsurface  distribution  of  the  effluent  are  outlined  in  figure  19:  (1) 
The  house  sewer  from  house  to  tank;  (2)  the  sewage  tank  consisting 
of  one  or  more  chambers;  (3)  the  sewer  from  tank  to  distribution 

9  Artificial  filters  of  various  types  are  well  described  and  illustrated  in  Public  Health 
Bulletin  No.  101.  "  Studies  of  Methods  for  the  Treatment  and  Disposal  of  Sewage — The 
Treatment  of  Sewage  from  Single  Houses  and  Small  Communities."  U.  S.  Public  Health 
Service.  December,  1919. 


Sewage  and  Sewerage  of  Farm  Homes. 


31 


field;  (4)  the  distribution  field,  where  the  sewage  is  distributed  and 
wasted,  sometimes  called  the  absorption  field.  These  parts  will  be 
discussed  in  the  order  named,  although  the  last  should  have  the  first 
consideration. 

House  sewer. — The  length  will  vary  with  the  slope  of  the  ground 
and  position  of  buildings,  well,  and  distribution  field.    Fifty  to  100 


Distribution   Tile 


House 


TankT 


Under  drain 
(if necessary) 


.-- J  Drainage 

in-r 


Outlet 


1051 


FIG.  19. — Parts  of  a  septic-tank  installation. 

feet  is  a  fair  length ;  a  greater  is  still  more  sanitary.  Wherever  pos- 
sible the  house  sewer  should  be  laid  straight  in  line  and  grade.  Fig- 
ure 20  shows  how  this  work  may  be  done.  Suppose  the  distance  from 
A  to  E  be  100  feet ;  that  grade  boards  be  set  25  feet  apart  crosswise 
of  the  trench  at  A,  B,  C,  D,  and  E;  that  the  ground  at  A  be  4  feet 
lower  than  at  E ;  that  the  top  of  the  sewer  be  2|  feet  below  the  surface 


B 


I3&I 

PIG.  20. — Setting  line  and  grade  for  house  sewer.     To  the  observer  at  A  the  top  edges 
of  the  grade  boards  appear  as  one ;  the  half-driven  nails  are  set  to  line. 

of  the  ground  at  A  and  4|  feet  below  the  surface  of  the  ground  at  E ; 
the  fall  of  the  sewer  between  A  and  E  is  2  feet  (4+2^— 4J=:2).  If 
the  fall  in  100  feet  be  2  feet,  in  25  feet  it  is  one-fourth  as  much,  or  6 
inches.  Hence,  grade  board  B  is  6  inches  higher  than  grade  board 
A,  C  is  (?  inches  higher  than  B,  and  so  on  to  E.  The  top  edges  when 
all  the  boards  are  set  with  a  carpenter's  level  and  fastened  in  position 
should  be  in  line.  The  grade  thus  established  may  be  any  con- 


32  Farmers'  Bulletin  1227. 

venient  height  above  the  top  of  the  proposed  sewer,  and  the  measur- 
ing stick  used  to  grade  the  pipe  is  cut  accordingly.  This  height  is 
usually  a  certain  number  of  whole  feet.  Fixing  the  line  of  the  sewer 
is  a  mere  matter  of  settling  nails  in  the  top  edges  of  boards  A  and  E 
directly  over  the  center  of  the  proposed  sewer  and  tightly  stretching 
a  fish  line  or  grade  cord;  nails  should  be  set  where  the  cord  crosses 
boards  B,  C,  and  D. 

If  the  cellar  or  basement  contains  plumbing  fixtures,  the  house 
sewer  should  enter  1  to  2  feet  below  the  cellar  floor.  If  all  plumbing 
fixtures  are  (5n  the  floors  above,  the  sewer  may  enter  at  no  greater 
depth  than  necessary  to  insure  protection  from  frost  outside  the  cel- 
lar wall.  Digging  the  trench  and  laying  the  pipe  should  begin  at  the 
tank  or  lower  end.  The  large  end  of  the  pipes,  called  the  hub,  should 
face  uphill,  and  the  barrel  of  each  pipe  should  have  even  bearing 
throughout  its  length.  Sufficient  earth  should  be  removed  from  be- 
neath the  hubs  to  permit  the  joints  to  be  made  in  a  workmanlike 
manner. 

The  house  sewer  may  be  vitrified  salt-glazed  sewer  pipe,  con- 
crete pipe,  or  cast-iron  soil  pipe.  The  latter,  with  poured  and  calked 
lead  joints  makes  a  permanently  water-tight  and  root-proof  sewer, 
which  always  should  be  used  where  the  vicinity  of  a  well  must  be 
passed ;  4,  5,  or  6-inch  pipe  may  be  used,  depending  mainly  on  the  fall 
and  in  less  degree  on  the  quantity  of  sewage  discharged.  As  a  meas- 
ure of  economy  the  4-inch  size  is  favored  for  iron  pipe.  If  vitrified 
pipe  is  used,  either  the  5  or  6  inch  size  is  preferable,  as  these  sizes  are 
made  straighter  than  the  4-inch  size  and  are  less  liable  to  obstruction. 
Of  the  two  the  5-inch  size  is  preferable.  The  fall  in  100  feet  should 
never  be  less  than  2  feet  for  4-inch  size,  H  feet  for  5-inch  size, 
1  foot  for  6-irich  size. 

Figure  21  shows  methods  of  making  good  joints.  A,  B,  G,  D,  E, 
F,  and  G  are  ordinary  sewer  pipe  joints;  H,  is  cast-iron  soil  pipe. 

A  shows  the  use  of  a  yarning  iron  to  pack  a  small  strand  of  jute  into  the 
joint  space,  thus  centering  the  pipes  and  preventing  the  joint  filler  running  inside. 
The  joint  surfaces  should  be  free  of  dirt  and  oil.  The  jute  is  cut  in  lengths  to 
go  around  the  pipe ;  a  small  strand  is  soaked  in  neat  Portland  cement  grout,  then 
twisted  and  wrapped  around  the  .small  end  of  the  pipe  to  he  pushed  into  the 
hub  of  the  last  pipe  laid.  After  the  pipe  is  pushed  home  the  jute  is  packed 
evenly  to  a  depth  of  not  over  \  inch,  leaving  about  14  inches  for  the  joint  filler. 
Old  hemp  rope  or  oakum  dipped  in  liquid  cement  or  paper  may  be  used  in  place 
of  jute,  and  the  packing  may  be  done  with  a  thin  file  or  piece  of  wood. 

fi  shows  the  use  of  a  rubber  mitten  or  glove  to  force  Portland  cement  mortar 
into  the  joint  space.  The  mortar  should  be  thoroughly  and  freshly  mixed  in  the 
proportion  of  one  volume  of  cement  to  one  volume  of  clean  sand  and  should  be 
pressed  and  tamped  to  fill  the  joint  completely. 

C  shows  a  section  of  finished  joint.  The  fresh  mortar  should  not  be  loosened 
or  disturbed  when  laying  the  next  pipe. 

D  shows  method  of  pouring  a  joint  with  grout,  which  is  quicker,  cheaper,  and 
better  than  using  a  rubber  mitten.  A  flexible  sheet-metal  form  or  mold,  oiled 
to  prevent  the  grout  sticking,  is  clamped  tightly  around  the  joint  and  is  com- 
pletely filled  with  grout  consisting  of  equal  parts  of  Portland  cement  and  clean 


Sewage  and  Seweraae  of  Farm  Homes.  33 

sand  mixed  dry,  to  which  water  is  added  to  produce  a  creamy  consistency.  The 
pipes  should  not  be  disturbed  and  the  form  Khould  not  be  removed  for  24  hours. 

/•;  shows  a  section  of  grouted  joint,  well  rounded  out,  strong,  and  tight. 

F  shows  the  use  of  a  pipe  jointer  for  pouring  a  hot  filler.  The  pipe  jointer 
may  be  an  asbestos  or  rubber  runner  or  collar  or  a  piece,  of  garden  hose  clamped 
around  the  pipe  leaving  a  small  triangular  opening  at  the  top.  The  jointer  is 
pressed  firmly  against  the  hub,  and  any  small  openings  between  the  jointer  and 
pipe  are  smeared  with  plastic  clay  to  prevent  leakage  of  the  tiller.  A  clay  dike 
or  funnel  about  3  inches  high  built  around  the  triangular  opening  greatly  aids 
rapid  and  complete  filling  of  the  joint  space.  The  filler  may  be  a  commercially 
prepared  bituminous  compound  or  molten  sulphur  and  fine  sand.  The  former 
makes  a  slightly  elastic  joint;  the  latter  a  hard  unyielding  joint.  With  good 
workmanship  both  kinds  of  joint  are  practically  water-tight  and  root-proof, 
and  cost  about  the  same  as  cement  mortar  joints.  The  filler  is  heated  in  an  iron 
kettle  over  a  wood,  coke,  or  coal  fire.  It  should  be  well  stirred,  and  when  at  a 
free  running  consistency  should  be  poured  with  a  ladle  large  enough  to  fill  the 
joint  completely  at  one  operation.  As  soon  as  the  compound  cools  the  jointer 
is  removed.  Sulphur-sand  filler  is  made  by  mixijig  together  dry  and  melting 
equal  volumes  of  ordinary  powdered  sulphur  and  very  fine  clean  sand,  pre- 
lerahly  the  finest  quicksand.  A  .~>-incli  sewer  pipe  joint  requires  from  three-tenths 
to  nine-tenths  of  a  pound  (according  to  the  kind  of  pipe)  of  sulphur,  worth  3  to 
T)  cents  per  pound,  and  a  like  quantity  of  sand.  From  £  to  1£  pounds  of  bitu- 
minous filler  are  required  for  a  5-inch  pipe  joint. 

G  shows  section  of  finished  joint. 

H  shows  the  use  of  a  pouring  ladle  in  making  lead  joints  in  cast-iron  soil  pipe. 
This  pipe  is  in  lengths  to  lay  5  feet,  and  the  metal  of  the  barrel  is  £  inch  thick. 
The  joint  is  yarned  with  dry  jute  or  oakum,  as  described  above,  and  is  poured 
full  with  molten,  soft,  pig  lead  to  be  afterwards  driven  tightly  with  hammer  and 
calking  tools.  About  1  pound  of  lead  for  each  inch  in  diameter  of  pipe  is 
required.  Prepared  cements  of  varying  composition  have  proved  effective  and, 
as  they  require  no  calking,  are  economical.  Among  the  best  is  a  finely  ground, 
thoroughly  mixed  compound  of  iron,  sulphur,  slag,  and  salt. 

/  is  a  homemade  pipe  jointer  or  clay  roll  for  use  in  pouring  molten  lead.  A 
strand  of  jute  long  enough  to  encircle  the  pipe  and  the  ends  to  fold  back,  leaving 
an  opening  at  the  top,  is  covered  with  clay  m< listened,  rolled,  and  worked  to  form 
a  plastic  rope  about  1  inch  in  diameter.  The  jointer  gives  the  very  best  results 
but  must  be  frequently  moistened  and  worked  to  keep  the  clay  soft  and  pliable. 
The  jointer  shown  in  F  is  frequently  used  for  pouring  lead  joints. 

Obstructions  in  house  sewers  are  frequent.  Among  the  causes 
are  broken  pipes,  grade  insufficient  to  give  cleansing  velocities,  news- 
paper, rags,  garbage,  or  other  solids  in  the  sewage,  congealing  of 
grease  in  pipes  and  main  running  traps  (house  sewer  traps),  and 
poor  joint  construction  whereby  rootlets  grow  into  the  sewer  and 
choke  it.  Good  grade  and  good  construction,  with  particular  care 
given  to  the  joints,  will  avert  or  lessen  these  troubles.  The  sewer 
should  be  perfectly  straight,  with  the  interior  of  the  joints  scraped 
or  swabbed  smooth.  When  the  joint-filling  material  has  set,  the 
hollows  beneath  the  hubs  should  be  filled  with  good  earth  free  of 
stones,  well  tamped  or  puddled  in  place.  It  is  important  that  like 
material  be  used  at  the  sides  of  the  pipe  and  above  it  for  at  least 
1  foot.  The  back  filling  may  be  completed  with  scraper  or  plow. 
No  running  trap  should  be  placed  on  the  house  sewer,  because  it 
is  liable  to  become  obstructed  and  it  prevents  free  movement  of  air 
through  the  sewer  and  soil  stack.  Conductors  or  drains  for  rain 
or  other  clean  water  should  never  connect  with  the  house  sewer, 
but  should  discharge  into  a  watercourse  or  other  outlet. 


34 


Farmers    Bulletin  1227. 


Where  obstruction  of  a   house  sewer  occurs,  use  of  some  of  the 

simple  tools  shown  in  figure  22  may  remedy  the  trouble.     It  is  not 

likely  that  farmers  will  have  these  appliances,  except  possibly  some 

of  the  augers;  but  some  of  them  can  be  made  at  home  or  by  a  black - 

\  smith,    and    most    of 


Jute 


\ 


B 


c 

Cem  ent  mortar  - 


Jute 


Grout  after  setting. 


Jute 


jointing 
compound^ 


I 

Strand  of  jute 


Plastic  clay 


1308 


them  should  be  ob- 
tainable for  tempo- 
ran;  use  from  a  well- 
organized  town  or 
city  sewer  depart- 
ment. The  purpose  of 
the  several  tools 
shown  is  indicated  in 
the  notation. 

The  tank..— The 
septic  tank  should  be 
in  an  isolated  location 
at  least  50  to  100  feet 
from  any  dwelling. 
This  is  not  always 
possible,  because  of 
flat  ground,  but  in 
many  such  instances 
reasonable  distance 
and  fall  may  be  se- 
cured by  raising  both 
the  house  sewer  and 
tank  and  embanking 
them  with  earth. 
Cases  are  known 
where  tanks  adjoin 
ce  1 1  a  r  or  basement 
walls  and  the  top  of 
the  tank  is  used  as  a 
doorstep ;  in  other 
cases  tanks  have  been 
constructed  within 
buildings.  Such  prac- 
tices are  bad.  It  is 


FIG.  21. — How  to  make  good  joints.     See  text  for  direo- 
tions  and  specifications. 

difficulty  to  construct  an  absolutely  water-tight  masonry  tank,  and 
still  more  difficult  to  make  it  proof  against  the  passage  of  sewage  odors. 
In  Northern  States,  particularly  in  exposed  situations,  it  is  de- 
sirable to  have  the  top  of  the  tank  1  to  2  feet  underground,  thus 
promoting  warmth  and  uniformity  of  temperature  in  the  sewage. 


Sewage  and  Sewerage  of  Farm  Homes. 


35 


In  Southern  States  this  feature  is  less  important,  and  the  top  of  the 
tank  may  be  flush  with  the  ground.  Every  tank  should  be  tightly 
covered,  for  the  reason  above  stated  and  to  guard  against  the  spread 

B  D 


-LJ- 


<T  <  C 


H 


or> 


LLLLLLUJ 


M 


1305 


K 


FIG.  22. — Sewer-cleaning  tools — how  to  use  them.  A,  Ordinary  1|  or  2  Inch  auger 
welded  to  a  piece  of  2 -inch  extra-strong  wrought  pipe  about  5  feet  long ;  the  stem  Is 
lengthened  by  adding  other  pieces  of  pipe  with  screw  couplings,  and  is  fitted  with  a 
pipe  handle;  all  cleaning  work  should  proceed  upstream  ;  B,  twist  or  open  earth  auger  ; 
C,  ribbon  or  closed  earth  auger ;  D,  spiral  or  coal  auger ;  E,  ship  auger  ;  F,  root  cutter  ; 
<?,  sewer  rods  with  hook  coupling,  usually  of  hickory  or  ash  1  or  1|  inches  in  diameter 
and  3  or  4  feet  long ;  //,  gouge  for  cutting  obstructions  ;  /,  scoop  for  removing  sand  or 
similar  material ;  J,  claw,  and  K,  screw,  for  removing  paper  or  rags;  L,  scraper; 
M,  wire  brush  for  removing  grease,  drawn  back  and  forth  with  a  wire  or  rope ;  N, 
home-made  wire  brush  (for  a  5-inch  sewer  use  a  1  i-inch  wooden  pole  to  which  is 
securely  tacked  a  piece  of  heavy  rubber,  canvas  or  leather  belting  or  harness  leather 
5i  by  8  inches,  spirally  studded,  as  shown,  with  ordinary  wire  nails  1|  inches  in 
length). 

of  odors,  the  transmission  of  disease  germs  by  flies,  and  accidents  to 
children. 

Considerable  latitude  is  allowable  in  the  design  and  construction 
of  septic  tanks.  No  particular  shape  or  exact  dimensions  can  be 
presented  for  a  given  number  of  people.  One  family  of  5  persons 


Fanners'  Ilnllctin   1227. 


may  use  as  much  water  as  another  family  of  10  persons;  hence  ihe 
quantity  of  sewage  rather  than  the  number  of  persons  is  the  better 
basis  of  design.  Exact  dimensions  are  not  requisite,  for  settlement 
and  septicization  proceed  whether  the  sewage  is  held  a  few  hours 
more  or  a  few  hours  less.  As  to  materials  of  construction  some  form 
of  masonry,  either  brick,  building  tile,  rubble,  concrete,  or  cement 
block,  is  employed  generally.  Vitrified  pipe,  steel,  and  wood  have 
been  used  occasionally. 

A  plant  for  use  all  year  round  should  have  two  chambers,  one  to 
secure  settlement  and  septicization  of  the  solids  and  the  other  to 
secure  periodic  discharge  of  the  effluent  by  the  use  of  an  automatic 
sewage  siphon.  The  first  chamber  is  known  as  the  settling  chamber, 
the  second  as  the  siphon  or  dosing  chamber.  The  siphon  chamber  is 
often  omitted  and  the  effluent  is  allowed  to  dribble  away  through  sub- 
surface tile,  as  illustrated  in  figures  IT  and  LS.  The  latter  procedure 
is  not  generally  advised,  but  may  be  permissible  where  the  land 
slopes  sharply  or  has  long  periods  of  rest,  as  at  summer  houses  and 
camps. 

The  septic  tanks  shown  in  this  bulletin  are  designed  to  satisfy 
the  following  conditions : 

1.  Water  consumption  of  40  gallons  per  person  per  day  of  24 
hours. 

2.  A  detention  period  of  about  24  hours ;  that  is,  the  capacity  of  the 
settling  chamber  below  the  flow  line  is  approximately  equal  to  the 

quanity   of   sewage 
discharged  from  the 

Double  plank  cover  — •>  __—        ,  •       C\A    i 

house  in  24  hours. 
3.  Where  a  si- 
phon chamber  is 
provided,  its  size  is 
such  that  the  close  of 
sewage  shall  be  ap- 
proximately equal 
to  20  gallons  per 
person;  that  is,  the 
capacity  qf  the  si- 
phon chamber  be- 
tween the  discharge 
and  low-water  lines 

FIG.    23.— One-chamber    septic    tank—does    nothing    more  ^  roug^l>T  equal   to 

than  a  tight  cesspool.     Brick  construction,  heavily  plas-  the  quantity  OT  SCW- 

tered    inside;    size    suitable    for    180    to    280    gallons   of  age     discharged      in 

sewage  daily   (nominally  4  to  7  persons).  |2  hours 

A  simple  one-chamber  brick  tank  suitable  for  a  household  discharg- 
ing 180  to  280  gallons  of  sewage  daily  is  shown  in  figure  23.  A 
small  two-chamber  tank  constructed  of  24-inch  vitrified  pipe,  suitable 
for  a  household  discharging  about  125  gallons  of  sewage  daily,  is 
shown  in  figure  24.  A  typical  two-chamber  concrete  tank  is  shown  in 
figure  25.  Excepting  the  submerged  outlet,  all  pipes  within  the  tank 


to  distribution 
trenches 


Port/and  cement 
p/asfer  coat 

4'-0" 
2' wide  inside 


Submerged 
otft/et 


Sewage  and  Sewerage  of  Farm  Homes. 


37 


and  built  into  the  masonry  are  cast-iron  soil  pipe  with  cast-iron  fit- 
tings. Vitrified  or  concrete  sewer  pipe  and  specials  are  generally 
used  as  they  are  frequently  more  readily  obtainable  and  a  slight 
saving  in  first  cost  may  be  effected.  Cast  iron  is  less  liable  to  be 
broken  in  handling  or  after  being  set  rigidly  in  masonry,  and  the 
joints  are  more  easily  made  water-tight.  The  submerged  outlet  is 
midway  of  the  depth  of  liquid  in  the  settling  chamber.  The  inside 
depth  of  the  siphon  chamber  is  the  drawing  depth  of  the  siphon 
plus  1  foot  5  inches. 

The,  following  table  gives  the  principal  dimensions  with  quantities 
of  materials  for  four  sizes  of  tank  as  illustrated  in  figure  25 : 

Dimension*  and  quantities  for  .vr/;//r  lunkx. 


Settling  chamber. 


Number  of  persons.    I  %^y 

'    age  in 
24  hours. 

Capacity 
below 
flow  line. 

Length. 

Depth. 

1 

Width.       W.          X. 

i 
1 

Y. 

Z. 

GaMs. 
5         180-280 

Galls. 
240 

Ft.    In. 
4      0 

Ft.    In. 
5      0 

Ft.    In.      In.      Ft.    In. 
20          6          20 

In. 

4 

In. 
6 

10                                             320-480 

420 

5      0 

.">      6 

26          6          23 

4 

6 

15  520-680 
20                                             720-960 

620 
860 

5      6 
6      0 

6      0 

6      6 

30          8          26 
3      6           8           29 

5 
5 

8 
8 

Num- 
ber 
of 
per- 
sons. 

Quan- 
tity of 
sewage 
in  24 
hours. 

Siphon  chamber. 

Con- 
crete. 

Ce- 
ment 

Sand. 

Stogie. 

Reinforcement 
in  top  slab 
(strip  of  heavy 
stock  fencing). 

Length. 

Depth. 

Width. 

A. 

In. 
3 
3 
4 
4 

B. 

c. 

In. 
15 
15 
17 
17 

D. 

In. 
18* 
18} 
20} 
20| 

Length. 

Width. 

5  
10.... 
15.... 
20.... 

Galls. 
180-280 
320-480 
520-680 
720-960 

Ft.  In. 
5      0 
8      0 
8      8 
10      0 

Ft.  In. 
2      8 
2      8 
2    10 
2    10 

Ft.  In. 
2      0 
2      6 
3      0 
3      6 

In. 
4 
4 
4 
4 

Cu.yds. 
3 

1 

Bbls. 
124 

Cu.yds. 

2 
3 
3* 

<**. 
P 

7 

Ft. 
10 
14 
15? 

17* 

In. 
32 
39 

47 
56 

Siphons. — Reference  has  already  been  made  to  the  vital  importance 
of  air  in  sewage  filtration.  If  the  spaces  within  a  filter  or  soil  are 
constantly  filled  with  water,  air  is  excluded,  and  the  action  of  the 
filtering  material  is  merely  that  of  a  mechanical  strainer  with  its 
clogging  tendency.  The  purpose  of  a  siphon  is  twofold:  (1)  To  se- 
cure intermittent  discharge,  thus  allowing  a  considerable  period  of 
time  for  one  dose  to  work  off  in  the  soil  and  for  air  to  enter  the  soil 
spaces  before  another  flush  is  received;  (2)  to  secure  distribution 
over  a  larger  area  and  in  a  more  even  manner  than  where  the  sewage 
is  allowed  to  dribble  and  produce  the  conditions  of  the  old-fashioned 
sink  drain — namely,  a  small  area  of  water-logged  ground. 

Three  types  of  sewage  siphon  are  shown  in  figure  26.  In  all,  the 
essential  principle  is  the  same :  A  column  of  air  is  entrapped  between 
two  columns  of  water ;  when  the  water  in  the  chamber  rises  to  a 
predetermined  height,  called  the  discharge  line,  the  pressure  forces 


38 


Farmers'  Bulletin  1227. 


FIG.  24. — Two-chamber  septic  tank,  simple  and  inexpensive.  Constructed  of  24-inch 
vitrified  sewer  pipe  ;  size  suitable  for  125  gallons  of  sewage  daily  (nominally  3  per- 
sons). A,  House  sewer;  B,  settling  chamber,  made  of  one  double  T  branch  and  one 
length  of  straight  pipe,  each  3  feet  long  and  2  feet  in  diameter,  supported  by  4  inches 
of  concrete,  all  joints  made  water-tight ;  C,  submerged  outlet,  consisting  of  a  metal  T 
slipped  into  the  sewer-pipe  branch  ;  D,  wire  screen,  JHnch  mesh ;  Ef  siphon  chamber 
made  of  one  T  branch  3  feet  long  and  2  feet  in  diameter  ;  F,  siphon  ;  G,  3-inch  over- 
flow ;  H,  sewer  to  distribution  field:  /,  tightcover  with  lifting-  ring:  J,  concrete  pro- 
tection around  sewer-pipe  hubs. 


/ Steel  reinforcemem 
V 


^Submerged 
J       outlet 

~T       Settling 
Chamber 


distribution  field  V;^ 


.    25. — Typical    two-chamber    concrete    septic    tank.      (See    table    for    dimensions   and 
quantities  for  different  sizes.) 


Sewage  and  Sewerage  of  Farm  Homes. 


39 


out  the  confined  air,  destroying  the  balance  and  causing  a  rush  of 
water  through  the  siphon  to  the  sewer.  The  entire  operation  is  auto- 
matic and  very  simple.  The  siphons  shown  are  commercial  products 
made  of  cast  iron;  they  have  few  parts  and  none  that  move,  and  the 


High  water  or 
Discharge   line 


Diameter  of  siphon  

2 

3 

INC 

1ES 

1  NCH  ES 

A 
B 
C 

n 

3 

4 
13 

!6'/< 

3 

4 
15 
IR'4 

4 
4 
14 
l7'/i 

4 
4 
17 
?0'/i 

3 

13 
17 
13 

19 
6 
13 
18 

3 

15 
17 
13 

21 
6 
13 
18 

4 

14 
19 

15 

20 
8 
II 
18 

4 

17 
22 

18 

25 
8 
12 
18 

Diameter  of  outlet.. 

Drawing  depth 

-- 

Depth  to  floor 

Height  above  floor        

F 
G 
H 

1 
J 

71A 
2 
20/2 

9/4 
2 
22/2 

83/4 
2 

22% 

N3/4 
2 

253/4 

— 

Clearance  under  bell 

/nside  bottom  ofout/et,  to  discharge  line. 
Discharge  line,  to  top  of  wall 

Depth  of  outlet  sump   ..   

Length  and  width  of  outlet  sump 

Diameter  of  carrier,  and  minimum 
fall  in  feet  per  100  feet 

^^^100  fT—  *»  + 
*2£r^\r"-^-^     S=  Minimum  fall 
^fc^^* 

R 
S 

4 
2ft. 

4 
2ft 

4 

7ft. 

4 

8ft. 

1306 

R 
S 

5 
l&ft 

5 
I'/zft. 

5 
2ft 

5 

2  '/2ft. 

R 
$ 

6 
Lfi, 

6 
Ift. 

6 
Ift. 

6 
Ift. 

FIG.  26. — Three  types  of  sewage  siphon.  The  table  gives  dimensions  for  setting  standard 
3  and  4  inch  siphons  ;  also  the  appropriate  size  and  grade  of  the  sewer  to  carry  the 
siphon  discharge. 

t 

whole  construction  is  simpie  and  durable.  The  table  (fig.  26)  lists 
stock  sizes  adapted  to  farm  use.  Manufacturers  furnish  full  infor- 
mation for  setting  their  siphons  and  putting  them  in  operation.  For 
example,  take  type  2,  figure  26:  (1)  Set  siphon  trap  (  U-shaped  pipe) 
plumb,  making  E  (height  from  floor  to  top  of  long  leg)  as  specified; 


40  Farmers'  Bulletin   1227. 

(2)  fill  siphon  trap  with  water  till  it  begins  to  run  out  at  B;  (3) 
place  bell  in  position  on  top  of  long  leg,  and  the  siphon  is  ready  for 
service.  Do  not  fill  vent  pipe  on  side  of  bell. 

The  overhead  siphon,  type  3,  figure  26,  may  be  installed  readily 
in  a  tank  already  built  by  addition  of  an  outlet  sump.  If  properly 
set  and  handled,  sewage  siphons  require  very  little  attention  and 
flush  with  certainty.  Like  all  plumbing  fixtures  the}7  are  liable  to 
stoppage  if  rags,  newspaper,  and  similar  solids  get  into  the  sewage. 
If  fouling  of  the  sniffing  hole  or  vent  prevents  the  entrance  of  suffi 
cient  air  into  the  bell  to  lock  the  siphon  properly,  allowing  sewage 
to  dribble  through,  the  remedy  is  to  clean  the  siphon.  Siphons  are 
for  handling  liquid;  sludge  if  allowed  to  accumulate  will  choke  thorn. 

Submerged  outlet. — The  purpose  of  a  submerged  outlet  is  to  take 
the  outflow  from  a  point  between  the  sludge  at  the  bottom  and  the 
floating  solids  or  scum.  The  outlet  in  figure  25  may  be  readily  made 
of  sheet  metal  by  a  tinsmith.  Wrought  iron  or  steel  pipe  with 
elbows  or  light  lead  pipe  may  be  used,  the  pipe  being  set  in  the 


f 


mesh  strips  /Q  "wide,  ^     |*-   22"£ ,.,f.       o-no 

about  fapound per  square  foot r^-iri,.?.».L-..-.'S«       ' 


1380 


FIG.  -7. — Homemade  reinforced  concrete  covers.  (1)  Slabs  placed  crosswise  permit  un- 
covering the  whole  tank  for  cleaning,  but  as  inspection  is  somewhat  difficult,  cleaning 
is  the  more  likely  to  bo  neglected;  (2)  manhole,  18  inches  square:  cover,  22  by  22  by  3 
inches  thick,  easy  to  make  and  to  slide  or  lift  from  the  opening. 

concrete  and  left  in  place.  Sometimes  a  galvanized  wire  screen 
(J-inch  mesh)  is  fitted  over  the  inner  end  to  prevent  large  solids 
leaving  the  settling  chamber  and  possibly  clogging  the  siphon  or 
distribution  tile.  If  a  screen  is  used  it  should  be  easily  removable 
for  cleaning. 

Manhole  frame  and  cover. — The  frame  and  cover  shown  in  figure  25 
are  stock  patterns  made  of  cast  iron  and  weighing  about  250  pounds 
per  set.  The  cover  is  21  inches  in  diameter:  it  is  tight  and,  on 
account  of  its  weight,  is  unlikely  to  be  disturbed  by  small  children. 
The  frame  or  rim  is  about  7  inches  high  and  31  inches  in  longest 
diameter.  If  desired,  light  cast-iron  cistern  or  cesspool" covers  ob- 
tainable from  plumbing  supply  houses,  home-made  slabs  of  rein- 
forced concrete  (see  fig.  27),  o»  wooden  covers  (see  fig.  23)  may  be 
used. 

Overflow. — The  purpose  of  an  overflow  is  to  pass  .sewage  to  the  dis- 
tribution field  should  the  siphon  stop  working.  The  overflow  (fig. 
25)  is  a  3-inch  riser  pipe  with  top  3  inches  above  the  discharge  line 
and  the  bottom  calked  or  cemented  into  the  side  outlet  of  a  T- 
branch.  The  run  of  the  T -branch  should  correspond  with  the  size 


Sewage  and  Sewerage  of  Farm  Homes.  41 

of  the  sewer  from  the  tank  to  the  distribution  field.  If  this  sewer 
is  4-inch  pipe,  a  4  by  3  inch  T  -branch  is  used,  the  4-inch  spigot  end 
of  the  siphon  being  calked  or  cemented  into  the  branch,  as  shown 
in  figure  25 ;  if  the  sewer  is  5-inch,  a  5  by  3  inch  T-branch  is  used 
and  connected  to  the  siphon  with  a  5 -inch  to  4-inch  reducer  (in 
vitrified  specials  the  equivalent  is  a  4-inch  to  5-inch  increaser)  ;  if 
the  sewer  is  6-inch,  a  6  by  3  inch  T-branch  is  used  and  connected 
to  the  siphon  with  a  6-inch  to  4-inch  reducer. 

Concrete  work. — Before  excavation  for  the  tank  is  begun,  two 
wooden  forms  should  be  built  for  shaping  the  inside  of  the  settling 
And  siphon  chambers.  In  most  instances  the  ground  is  fairly  firm, 
so  that  the  lines  of  excavation  may  conform  to  the  outside  dimen- 
sions of  the  tank,  the  back  of  the  walls  being  built  against  the  earth. 
The  forms  may  be  made  of  square-edged  boards,  braced  and  lightly 
nailed,  as  shown  in  figure  28.  The  forms  should  have  no  bottom. 
If  it  is  desired  to  lay  the  sides  and  covering  slab  in  one  operation, 
the  top  of  the  forms  must  be  boarded  over.  All  pipe  and  manhole 
openings  should  be  accurately  placed  and  cut.  The  faces  of  the 
forms  may  be  covered  with  paper  or  smeared  with  soap  or  grease  to 
facilitate  removal  later. 

The  ground  should  next  be  excavated  to  the  proper  depth  for 
placing  the  floors  in  both  chambers.  The  settling  chamber  floor, 
being  the  lower,  should  be  placed  first.  Effort  should  be  made  to 
secure  water-tight  work,  a  feature  of  especial  importance  where 
leakage  might  endanger  a  well  or  spring.  A  concrete  mixture  of 
1:2:4  is  generally  preferred  (1  volume  cement,  2  volumes  sand,  4 
volumes  stone).  The  ingredients  should  be  of  best  quality  and  thor- 
oughly mixed.  The  concrete  should  be  poured  promptly  and  worked 
with  a  spade  or  flat  shovel  to  make  the  face  smooth  and  eliminate 
pockets  or  voids  within  the  mass.10  Before  the  settling  chamber  floor 
has  hardened  the  form  should  be  set  upon  the  floor  and  the  concrete 
work  continued  up  the  sides.  The  pipe  form  for  the  submerged 
outlet  should  be  set.  When  the  side  walls  of  the  settling  chamber 
have  reached  the  bottom  of  the  excavation  for  the  siphon  chamber, 
the  siphon  trap  with  its  connecting  branch  and  short  piece  of  pipe 
should  be  set  to  proper  line  and  grade  and  blocked  in  position.  The 
floor  of  the  siphon  chamber  should  now  be  poured  and  the  form  for 
that  chamber  placed  thereon,  leaving  a  6-inch  or  8-inch  space  (ac- 
cording to  the  thickness  of  the  division  wall)  between  the  ends  of 
the  two  forms.  Pouring  of  all  side  walls  and  the  top  slab  should 
continue  without  stop,  making  the  entire  structure  a  monolith. 

Steel  reinforcement. — To  stiffen  the  cover  slab  and  guard  against 
cracking,  a  little  steel  should  be  embedded  in  the  concrete  about  1 

10  See  footnote,  p.  17.  For  more  detailed  information  on  form  and  concrete  work  the 
reader  is  referred  to  U.  S.  Department  of  Agriculture  Farmers'  Bulletin  No.  481,  "  Con* 
crete  Construction  on  the  Live-Stock  Farm." 


42 


Farmers'  Bulletin  1227. 


inch  above  the  inside  top.    For  this  purpose  a  strip  of  heavy  stock 
fencing  is  convenient  and  inexpensive.    The  line  wires  should  be  not 


,.. 
Thickness  of  division  wa// 


1344 


FIG.  28. — Forms  for  concrete  work — bow  to  use  them. 

1.  Make  the  forms  as  shown  and  to  the  dimensions  required  by  fig.  25  and  the  table 
on  p.  37  ;  nails  to  be  driven  from  the  inside  and  left  projecting  sfor  drawing  with  a  claw 
hammer. 

2.  Excavate  to  lines  6  or  8  inches,  as  may  be  required,  outside  of  the  forms  and  to 
the  depths  required  for  both  chambers. 

3.  Pour  settling  chamber  floor  and  place  form  thereon. 

4.  Pour  settling  chamber  walls  to  level  of  siphon  chamber  excavation,   inserting  sub- 
merged outlet  pipe  at  the  proper  height. 

5.  Block  siphon  trap  and  connected  branch  and  short  pipes  to  correct  line  and  grade, 
and  fill  with  concrete  around  the  trap. 

6.  Pour  siphon  chamber  floor,  and  place  the  form  thereon. 

7.  Continue  pouring  all  walls  to  their  full  height,  inserting  the  inlet  pipe  when  the 
concrete  reaches  that  elevation. 

8.  Do  not  remove  forms  till  the  concrete  is  hard  ;  with  favorable  weather,   forms  for 
walls  only  may  be  removed  in  1  to  2  days  ;  forms  supporting  a  cover  slab  should  remain 
1  to  2  weeks. 

less  than  No.  10  gauge   (about  -J  inch)  and  the  stay  wires  not  less 
than  No.  11  gauge.    The  reinforcement  should  be  cut  at  manholes  and 


Sewage  and  Sewerage  of  Farm  Homes.  43 

fastened  around  manhole  openings.  If  desired  a  standard  wire-mesh 
reinforcement  weighing  about  one-third  of  a  pound  per  square  foot 
may  be  used.  Another  alternative  is  to  use  J-inch  round  rods, 
spacing  the  crosswise  rods  6  inches  apart  and  the  lengthwise  rods 
12  inches  apart.  Poultry  netting  should  not  be  used,  because  of 
its  lightness. 

Sewer  from  tank  to  distribution  field. — The  length  of  this  sewer 
depends  on  the  situation  of  the  field  and  the  fall  to  it.  The  size  of  the 
sewer  depends  on  the  fall  that  can  be  obtained  and  the  size  of 
siphon.  The  table  in  figure  26  shows  the  minimum  fall  at  which 
4-inch,  5-inch,  and  6-inch  sewers  should  be  laid  to  take  the  discharge 
of  the  3-inch  and  4-inch  siphons  specified.  The  line  and  grade 
should  be  set  in  the  same  manner  as  for  the  house  sewer  (see  fig.  20), 
and  the  construction  should  be  as  specified  under  that  caption. 

Distribution  field. — The  distribution  field  or  area  is  a  sewage  filter, 
and  its  selection  and  the  manner  of  preparing  it  largely  determine 
the  success  of  subsoil  disposal  of  sewage.  As  a  rule  farm  land 
is  not  the  best  filtering  material.  It  is  too  fine  grained  and  fertile. 
Its  tendency  is  to  hold  water  too  long,  to  admit  insufficient  air,  to 
clog  when  even  small  quantities  of  sewage  are  applied.  Hence  the 
distribution  area  should  be  of  liberal  size — on  the  average  500  square 
feet  for  each  person  served.  It  should  be  dry,  porous,  and  well 
drained — qualities  that  characterize  sandy,  gravelly,  and  light  loam 
soils.  It  should  be  devoid  of  trees  and  shrubbery,  thus  giving  sun- 
light and  air  free  access.  It  should  be  located  at  least  300  feet  down- 
hill from  a  well  or  spring  used  for  domestic  water  supply.  Pref- 
erably it  should  slope  gently,  but  sharp  slopes  are  not  prohibitive. 
Subsoiling  the  area  is  always  desirable. 

Clay  and  other  compact,  impervious  soils  require  special  treat- 
ment. Less  sewage  can  be  applied  to  them,  and  hence  it  is  well  to 
have  the  area  larger  than  500  square  feet  per  person.  Clay  should 
be  subsoiled  as  deep  as  possible  with  a  subsoil  plow.  In  some  in- 
stances dynamite  has  been  of  service  in  opening  up  the  ground  to* 
still  greater  depth.  Drainage  and  aeration  should  be  further  pro- 
moted by  laying  tile  underdrains,  as  outlined  in  figure  19  and  shown 
in  more  detail  in  figure  31. 

After  the  construction  work  the  distribution  area  should  be  raked 
and  seeded  with  thick-growing  grass.  Grass  is  a  safe  crop ;  its  water 
requirement  is  high,  and  it  affords  considerable  protection  from  frost. 
Suitable  grasses  are  redtop,  white  clover,  blue  grass,  and  Bermuda 
grass.  The  area  may  be  pastured  or  kept  as  grass  land. 

Distribution  system.— Poor  distribution  of  the  sewage  and  failure  to 
protect  the  joints  of  the  distribution  tile  account  for  most  of  the 
failures.  Each  flush  of  the  siphon  should  be  so  controlled  that  every 
part  of  the  field  will  receive  its  due  proportion.  The  distribution 


44  Farmers'  Bulletin  1227. 

tile  must  be  so  laid  that  loose  dirt  will  not  fall  or  wash  into  the  open 
joints. 

Different  methods  of  dividing  the  fltfsh  and  laying  out  the  distri- 
bution tile  are  shown  in  figures  29  and  32.  Layouts  1,  2,  and  3,  figure 
29,  are  suitable  for  flat  or  gently  sloping  areas  and  are  planned  for 
the  shallow  siphon  chambers  tabulated  on  page  37.  Layout  4,  fig- 
ure 29,  is  suitable  for  steep  slopes.  In  all  four  layouts  use  is  made  of 
one  or  more  V-branches  (not  Y-branches)  to  divide  the  flow  equally 
among  the  several  lines.  V-branches,  sometimes  called  breeches, 
should  be  leveled  with  a  carpenters  level  crosswise  the  ends  of  the 
legs,  thus  insuring  equal  division  of  the  flow. 

The  size  and  length  of  distribution  tile  and  the  spacing  of  the  lines 
or  runs  admit  of  considerable  variation  in  different  soils.  Water 
sinks  rapidly  in  gravels  and  sands,  and  hence  larger  tile  and  shorter 
length  are  permissible  than  in  close  soils.  Lateral  movement  is  slow 
in  all  soils,  but  extends  farther  in  gravels  and  sands  than  in  close 
soils.  In  average  soils  the  effect  on  vegetation  5  feet  away  from  the 
line  is  practically  nil. 

From  these  considerations,  with  the  siphon  dose  20  gallons  per 
person,  it  is  usually  a  safe  rule  to  provide  50  feet  of  3-inch  tile  for 
each  person  served  and  to  lay  the  lines  10  feet  apart.  Such  pro- 
vision gives  a  capacity  within  the  bore  of  the  tile  lines  about  equal 
to  the  siphon  dose,  and  as  some  sewage  is  wasted  at  each  joint  a 
reasonable  factor  of  safety  is  provided.  A  spacing  of  10  feet  will, 
it  is  believed,  permanently  prevent  the  extension  of  lateral  absorption 
from  line  to  line,  provided  the  area  is  fairly  well  drained.  As  be- 
tween 3-inch  and  4-inch  tile  the  smaller  size  costs  less  and  is  bet- 
ter calculated  to  taper  the  dose  to  small  proportions.  Four-inch  tile 
is  less  likely  to  get  out  of  alignment  or  to  become  clogged ;  a  length 
of  28  feet  has  the  same  capacity  in  the  bore  as  50  feet  of  3-inch. 

Good-quality  drain  tile  in  1-foot  lengths  or  second-quality  sewer 
pipe  in  2-foot  lengths  may  be  used.  The  lines  are  generally  laid  in 
•parallel  runs,  but  may  be  varied  according  to  the  topography.  Lay- 
outs 1,  2,  and  3,  figure  29,  for  flat  or  gently  sloping  land,  run  with 
the  slope;  layout  4,  for  steep  slopes,  runs  back  and  forth  along  the 
contour  in  a  series  of  long  flat  sweeps  and  short  steep  curves.  The 
grade  of  the  runs  and  sweeps  should  be  gentle,  rarely  more  than 
10  or  12  inches  in  100  feet.  In  layouts  1,  2,  and  3,  figure  29  espe- 
cially, it  is  desirable  that  the  last  20  feet  of  each  run  should  be  laid 
level  or  given  a  slight  upward  slope,  thus  guarding  against  undue 
flow  of  sewage  to  the  lowest  ends  of  the  system. 

The  runs  should  be  laid  no  deeper  than  necessary  to  give  clearance 
when  plowing  and  prevent  injury  from  frost.  Ten  inches  of  earth 
above  the  top  of  the  tile  is  sufficient  generally  throughout  the  south- 


Sewage  and  Sewerage  of  Farm  Homes. 


45 


*—  I  Oft  — -—  /0/X  — — /0/X  — | 


—  10  ft. — -j 


FIG.  29. — Methods  of  laying  distribution  system  :  Methods  1,  2,  and  3  for  flat  or  gently 
sloping  land;  method  4  for  steep  slopes  (see  also  fig.  32)  ;  A,  direction  of  slope;  B, 
contour  of  field ;  C,  sewer  from  tank,  preferable  size  ^  iach,  though  4  or  6  inch  may 
be  used,  depending  on  the  fall  and  the  size  of  the  siphon  (see  table,  fig.  26)  ;  D, 
V -branch  set  to  divide  the  flow  exactly  ;  E,  reducer,  to  4  inches  ;  F,  i  bend,  4 -inch;  G, 
increaser,  from  4  inches ;  H,  incrcascr,  3  to  4  inches ;  /,  reducer,  4  to  3  inches ;  J,  dis- 
tribution tile,  3-inch  ;  K,  distribution  tile,  4-inch. 


46 


Farmers'  Bulletin  1227. 


ern  half  of  the  United  States  and  18  inches  generally  in  the  North, 
but  if  the  field  is  exposed  or  lacks  a  thick  heavy  growth  of  grass  the 
cover  should  be  increased  to  2^  or  3  feet  near  the  Canadian  line. 
What  is  better,  the  tile  in  all  instances  may  be  laid  with  a  10-inch 
cover  and  in  cold  weather  the  runs  may  be  covered  with  hay,  straw, 
or  leaves  weighted  down,  which  may  be  removed  in  the  spring. 

Making  the  joints  of  the  distribution  tile  demands  especial  atten- 
tion. For  a  short  distance  on  the  upper  end  of  each  run  the  tile 
should  be  laid  with  ends  abutting;  the  joint  opening  should  be  in- 


1326 


FIG.  30. — Four  methods  of  protecting  open  joints  in  distribution  lines — an  all-important 
work.  Sketches  show  cross-section  and  longitudinal  views  ;  the  depth  from  the  surface 
of  the  ground  to  the  top  of  the  tile  is  about  10  inches. 

1.  A,  Subsoiled  ground;  B,  3  or  4  inch  drain  tile;  C,  strip  of  tarred  paper  about  6 
inches  wide  and  extending  three-fourths  the  distance  around  the  tile,   alloAvirtg  sewage 
to  escape  at  the  bottom  ;  D,  coarse  sand,  gravel,  broken  stone  or  brick,  slag,  cinders,  or 
coke,  the  coarsest  material  placed  around  the  tile   (where  the  ground  is  naturally  very 
porous  and  well  drained,  special  filling  in  the  trench  may  be  omitted)  ;   E,  natural  soil. 

2.  Drain  tile  covered  with  a  board  laid  flat,  leaving  the  entire  joint  open. 

3.  Drain  tile  laid  in  stoneware  gutter  pieces   and  the  joint  covered  with  stoneware 
caps  ;  gutter  and  cap  pieces  are  inexpensive  commercial  products  ;  their  radius  is  longer 
than  that  of  the  outside  of  the  tile,  thus  leaving  open  most  of  the  joint  space  ;  the  gutter 
aids  in  keeping  the  tile  in  line. 

4.  Vitrified  sewer  pipe  with  hubs  facing  downhill ;  the  spigot  end  should  be  centered 
in  the  hub  with  a  few  small  chinks  or  wedges. 

creased  gradually  to  one-eighth  inch  and  this  increased  to"  one-fourth 
in  the  last  20  feet  of  the  run.  All  joints  should  be  protected  against 
the  entrance  of  loose  dirt.  Four  methods  are  shown  in  figure  30. 
The  lower  end  of  each  run  should  be  closed  with  a  brick  or  flat 
stone ;  or,  what  is  better,  an  elbow  or  T-branch  may  be  placed  on  the 
end  and  vented  above  the  surface  of  the  ground,  improving  the  flow 
of  sewage,  the  ventilation  of  pipes,  and  the  aeration  of  the  soil. 

If  the  distribution  tile  must  be  laid  in  clay  or  other  close,  poorly 
drained  soil,  special  treatment  is  necessary.    A  common  method  is 


Sewage  and  Sewerage  of  Farm  Homes. 


47 


to  subsoil  and  underdrain  the  area  thoroughly,  as  shown  in  figure  31. 
It  is  not  always  possible  to  run  the  underdrain  in  lines  between  the 
distribution  lines  as  shown  in  figures  19  and  31,  but  it  is  a  desirable 
thing  to  do,  as  the  sewage  must  then  receive  some  filtration  through 
natural  soil. 

In  some  instances  it  is  sufficient  to  lay  the  distribution  tile  on  a  con- 
tinuous bed,  8  to  12  inches  thick,  of  coarse  gravel,  broken  stone,  or 
brick,  slag,  coke,  or  cinders  and  complete  the  refill  as  shown  in  figure 
18  or  31. 

Figure  32  shows  two  other  methods  of  controlling  the  flow  on  steep 
slopes  and  diverting  proper  proportions  to  the  several  lateral  distrib- 
utors laid  along  the  contour  of  the  field.  This  work  can  not  be 
effected  properly  with  T  or  Y  branches;  the  flow  tends  to  shoot 
straight  ahead,  comparatively  little  escaping  laterally.  To  overcome 


FIG.  31. — Close  soils  should  be  deeply  subsoiied  and  underdrained.  Porous,  well-drained, 
air-filled  soil  is  absolutely  necessary.  A,  Subsoiied  ground ;  B,  3  or  4  inch  distribution 
tile;  c,  depth  variable  with  the  climate,  1|  to  3*  feet;  D,  4-inch  underdrain;  17,  depth 
such  as  would  prepare  land  for  good  crop  production,  generally  3i  to  4  feet ;  F,  stone 
or  other  coarse  material ;  Gr,  gravel  grading  upward  to  coarse  sand ;  H,  loose  soil. 

this  difficulty  recourse  is  had  to  diverting  boxes,  of  which  two  types 
are  shown  in  figure  32.  These  boxes  involve  expense,  but  permit 
inspection  and  division  of  the  flow  according  to  the  needs.  They  may 
be  built  of  brick,  stone,  concrete,  or  even  wood. 

Type  1  consists  of  a  single  box,  into  which  all  the  lateral  distrib- 
utors head.  It  will  be  noted  that  the  laterals  enter  at  slightly  dif- 
ferent elevations,  the  two  opposite  the  inlet  sewer  being  the  highest, 
the  next  two  slightly  lower,  and  the  next  two  the  lowest.  This  stag- 
gering of  the  outlets,  in  a  measure,  offsets  the  tendency  of  the  flow 
to  shoot  across  and  escape  by  the  most  direct  route. 

Type  2  calls  for  one  or  more  diverting  boxes,  according  to  the  num- 
ber of  lateral  distributors,  and  readily  permits  of  wasting  sewage  at 
widely  separated  elevations  and  distances.  The  outlet  pipes  enter 
the  box  at  slightly  different  elevations,  for  the  reason  already  stated. 
With  either  type,  should  the  outlets  not  be  set  at  the  right  elevations. 


48 


Farmers'  Bulletin  1227. 


partial  plugging  of  the  holes  and  a  little  experimenting  will  enable 
one  to  equalize  or  proportion  the  discharges. 

Sewage  switch. — The  clogging  of  filters  and  soils  after  long- 
continued  application  of  sewage  has  been  previously  referred  to.  It 
is,  therefore,  desirable  to  arrange  the  distribution  system  in  two  units 
with  a  switch  between  them,  so  that  one  area  may  drain  and  become 


1325 


Plan  of  Diverting  Box 


'/a 


Cross  Section  of  Diverting  Box 


Cross  Section 


FIG.  32. — Two  systems  of  distribution  on  steep  slopes — use  of  diverting  box.  A,  Direc- 
tion of  slope  ;  B,  contour  of  field  ;  C,  4,  5  or  6  inch  sewer  from  tank  ;  D,  diverting  box ; 
E,  3-inch  or  4-inch  distribution  tile. 

aerated  while  the  other  is  in  use.  This  procedure  is  especially  de- 
sirable where  the  soil  is  close  and  the  installation  of  considerable 
size.  It  adds  to  the  life  and  effectiATeness  of  the  distribution  area  and 
permits  use  of  a  plant  in  case  it  is  necessary  to  repair,  extend,  or  re- 
lay the  tile  in  either  unit. 

Arrangement  in  two  units  does  not  necessarily  mean  doubling  the 
amount  of  tile  and  the  area  required  in  a  single  field.    However  de- 


Sewage  and  Sewerage  of  Farm  Homes. 


49 


sirable  that  may  be,  expense  or  lack  of  suitable  ground  will  often 
prevent.  With  open  sands  and  gravels  and  the  assumed  siphon  dose 
of  20  gallons  per  person,  15  to  20  feet  of  4-inch  tile  in  each  unit  for 
each  person  will  usually  suffice.  With  more  compact  soil  it  is  ad- 
visable to  more  nearly  double  the  requirements  previously  described. 
Two  simple  types  of  switch  are  shown  in  figure  33.  The  switch 
should  be  turned  frequently,  certainly  as  often  as  is  necessary  to  pre- 
vent saturation  or  bogginess  of  either  area. 


Plan 


Plan 


Cross  Section 


Cross  Section 


FIQ.  33. — Two  simple  types  of  sewage  switch.  A,  Sewer  from  tank  ;  B,  switch  box ;  C, 
cover  ;  D,  blade  or  stop  board  (in  the  left-hand  box  the  direction  of  flow  is  controlled 
by  placing  the  blade  in  alternate  diagonal  position  ;  in  the  right-hand  box  the  stop 
works  in  iron  guides  cast  integral  with  a  short  piece  of  light-weight  pipe  set  in  the 
masonry ;  if  desired  the  guides  may  be  wood,  fastened  to  the  masonry  with  expansion 
bolts)  ;  E,  sewer  to  distribution  area;  F  (right-hand  box),  alternate  position  of  outlets 
or  additional  outlets  if  required. 

A  complete  installation.— The  general,  lay  out  and  working  plans  of 
a  complete  installation  built  in  1915-16  are  shown  in  figure  34.  The 
plant  is  larger  than  those  heretofore  considered,  and  involves  several 
additional  features.  The  settling  chamber  below  the  flow  line  has 
a  capacity  of  1,000  gallons,  and  on  a  basis  of  40  gallons  per  person 
per  day  would  serve  25  people. 

For  many  years  sewage  had  been  discharged  through  two  4-inch 
sewers  to  a  cesspool  in  the  rear  of  the  house.  The  proximity  of  the 
well  made  it  unsafe,  and  the  overflow  of  tint:  cesspool  dribbled  over 
the  low  portion  of  the  garden  and  barnyard,  creating  nuisance. 


50 


Farmers'  Bulletin  1227. 


The  first  step  was  to  make  borings  with  a  soil  auger  in  the  pasture 
400  or  500  feet  from  the  house.  The  borings  showed  a  heavy  clay 
soil  to  a  depth  of  about  4  feet,  underlaicj.  with  a  sandy  stratum  only 
a  few  inches  in  thickness.  It  was  decided  to  locate  the  distribution 

Cast  iron  frame 
perforatedcover, 


f  Blade 
jj  about 
7x7' 
i/athick 


Cross  Section  of 
Switch  Box 


777  feet  ** —          215  feet 

PROFILE  OF  HOUSE  SEWER 


Cast  iron  frame 
tight   cover^ 


-4"sludae 
drain 


5"house 
(-sewer 

Elevation 
24.76 


1314 


Section  A-A 


6  "sewer 

4"s/phon         to  switch  box 
drawing  depth  2-9" 

All  pipes  se+  in  masonry 
are  galvanized,  or  cast  iron 

Longitudinal  Section  of  Septic  Tank 


FIG.  34. — A  complete  installation  for  a  large  rural  home.  General  layout  on  a  contour 
plan  and  construction  drawings.  Note  abandonment  of  old  cesspool  near  the  well  and 
garden  and  removal  of  sewage  to  a  lower  and  safer  location  in  the  pasture,  where  the 
treatment  is  subsurface  distribution,  aided  by  numerous  filter  wells  about  4  feet  deep 
filled  with  coarse  gravel.  Note  that  sludge  is  removed  from  the  bottom  of  the  settling 
chamber  by  opening  the  gate  on  the  sludge  drain. 

area  in  the  pasture  and  to  aid  the  seepage  of  sewage  by  digging 
numerous  filter  wells  through  the  clay  to  the  sandy  stratum.  Levels 
were  taken  and  a  contour  plan  prepared  to  serve  for  laying  out  the 
plant  and  establishing  the  grades. 


Sewage  and  Sewerage  of  Farm  Homes.  51 

The  septic  tank  is  built  in  one  corner  of  the  barnyard,  and  a  5-inch 
sewer  connects  it  with  the  old  4-inch  sewers  to  the  cesspool.  All 
sewer  pipe  joints  were  poured  with  a  flexible  jointing  compound. 
The  settling  chamber  is  of  hopper  shape  at  the  bottom,  and  a  4-inch 
sludge  drain  with  gate  provides  for  the  gravity  removal  of  sludge. 
The  lower  end  of  the  sludge  drain  is  above  the  surface  of  the  ground 
and  9  feet  below  the  flow  line.  The  end  is  protected  by  a  small 
retaining  wall,  and  the  sludge  is  readily  caught  in  barrels  and 
"hauled  out  on  the  land  for  burial.  The  outlet  is  low  enough  to  drain 
the  settling  chamber  completely.  If  it  is  desired  merely  to  force  out 
the  sludge,  the  drain  may  be  brought  to  the  surface  under  a  head 
of  3  to  5  feet,  discharging  the  sludge  into  a  trench  or  drying  bed,  to 
be  applied  later  to  the  land.  A  2-inch  waste  pipe  about  mid-depth 
of  the  settling  chamber  permits  drawing  off  the  clearer  portion  of 
the  sewage  to  the  siphon  chamber  and  from  thence  through  another 
2-inch  waste  pipe  into  the  6-inch  sewer  leading  to  the  distribution 
field. 

The  4-inch  siphon  has  a  drawing  depth  x>f  33  inches,  and  as  the 
siphon  chamber  is  4  feet  wide  by  6  feet  long  the  .dose  is  about  500 
gallons.  The  siphon  cost  $35.  The  6-inch  sewer  to  the  switch  box 
falls  about  6  inches  in  50  feet.  The  distribution  field  was  thor- 
oughly subsoiled,  and  about  800  feet  of  3-inch  tile  was  laid  in  each 
unit.  At  intervals  of  25  feet  along  the  distribution  trenches  6-inch 
holes  were  dug  through  the  clay  stratum  with  a  pesthole  digger. 
These  holes  were  filled  with  stone  and  constitute  the  filter  wells  previ- 
ously mentioned.  All  tile  lines  are  surrounded  with  stone  and  coarse 
grave^  and  the  ground  has  been  trimmed  to  give  a  uniform  cover  of 
12  inches.  All  work  was  done  by  day  labor  in  a  thorough  manner. 
As  the  men  were  doing  other  work  at  the  same  time  the  actual  cost 
is  not  known,  but  it  is  believed  the  installation  cost  about  $700. 

Cost  data. — Reliable  cost  figures  are  difficult  to  estimate.  Labor, 
materials,  freight,  haulage,  and  other  items  vary  greatly  in  different 
localities.  The  septic  tank  shown  in  figure  23  contains  about  1,000 
bricks  and  is  estimated  to  cost  $60  complete.  The  septic  tank  shown 
in  figure  25  for  5  persons  is  estimated  to  cost  $135;  for  10  persons, 
$170 ;  for  15  persons,  $240 ;  for  20  persons,  $280.  In  Maryland,  in 
1916,  the  cost  of  installing  a  septic  tank  similar  to  that  shown  in 
figure  25  (for  5  people),  including  86  feet  of  5-inch  house  sewer  (55 
feet  of  cast-iron  pipe  passing  a  well,  and  31  feet  of  vitrified  pipe) 
and  214  feet  of  second-quality  4-inch  sewer  pipe  in  the  distributon 
area,  was  as  follows: 

Excavation,  labor $7.  50 

Materials  delivered 46.  60 

Three-inch  siphon,  including  freight * 15.75 

Construction,  labor 28.00 

Supervision 5. 00 

Total..  -   102.85 


52 


Farmers'  Bulletin  1227. 


The  quotations  in  the  following  table  will  be  found  useful  in 
making  estimates  of  cost : 


Cost  of  pipe  and  dratoi  tile. 
(February,   1921.) 


Kind  of  pipe. 

Size,  in  inches. 

3             4 

5 

6 

Extra  heavy  cast-iron  soil  pipe,  on  cars  Chicago,  111.,  or  Washington, 
D.  C                         .                        Derfoot.. 

SO.  34 
.15 
.12 
.03 
.04 

$0.46 
.15 
.12 
.03£ 
.05 

$0.61 
.22J- 
.18 
.04*- 
.06 

80.  72 
.22* 
.18 
.05* 
.07 

Vitrified  salt-glazed  sewer  pipe  on  cars  Chicago  111 

do 

Vitrified  salt-glazed  sewer  pipe,  at  factory  near  Washington, 
Clay  or  shale  drain  tile,  at  factory  in  Ohio           

D.C.do.... 
...do... 

Clay  or  shale  drain  tile  at  factory  near  Washington  D  C 

do 

The  cost  of  cast-iron  fittings  may  be  roughly  estimated  as  follows : 
Bends,  one  to  one  and  one-half  times  the  price  of  straight  pipe ;  T- 
branches,  two  times  the  price  of  straight  pipe ;  reducers,  average  of 
the  prices  of  straight  pipe  at  each  end.  The  cost  of  clay  bends , 
T-branches,  reducers,  and  increasers  may  be  roughly  estimated  at 
four  times  the  price  of  straight  pipe. 

Operation. — Attention  must  be  given  to  every  plant  to  insure  suc- 
cess. Unusual  or  excessive  foulness  should  be  investigated.  No 
chemicals  should  be  used  in  a  septic  tank ;  garbage,  rags,  newspaper, 
and  other  solids  not  readily  soluble  in  water  should  be  kept  out  of 
sewers  and  tanks.  The  plant  should  be  inspected  often,  noting  par- 
ticularly if  the  siphon  is  operating  satisfactorily.  If  scum  forms 
in  the  settling  chamber  it  should  be  removed,  and  the  sludge  should 
be  bailed  or  pumped  out  yearly.  Frequently  tanks  are  not  cleaned 
out  for  three  or  four  years,  resulting  in  large  quantities  of  solid 
matter  going  through  to  the  distribution  system  and  clogging  it. 
Clogging  may  occur  in  the  tile  or  in  the  adjacent  soil.  In  either 
case  the  tile  should  be  dug  up,  cleaned,  and  relaid.  In  some  cases 
it  has  been  found  advantageous  to  relay  the  tile  between  the  former 
lines.  When  sewage  is  applied  to  fairly  porous  land  at  the  slow 
rate  here  recommended  and  the  plant  is  well  handled  the  tile  lines 
should  operate  satisfactorily  for  many  years.  Liming  heavy  soils 
tends  to  loosen  and  keep  them  sweet. 

Field  data. — As  a  basis  for  outlining  or  designing  a  suitable  installa- 
tion the  following  data  should  be  known : 

1.  State,  town,  and  whether  in  or  near  an  incorporated  munici- 
pality. 

2.  Usual  number  of  persons  to  be  served. 

3.  Average  daily  consumption  of  water  in  gallons. 

4.  Kind  and  depth  of  well,  depth  to  water  surface. 

5.  Character   of   soil,   whether   sandy,   gravelly,   loamy,   clay,   or 
muck. 

6.  Condition  of  soil  as  to  drainage. 


Sewage  and  Sewerage  of  Farm  Homes.  53 

7.  Character  of  subsoil. 

8.  Character  of  underlying  rock  and,  if  known,  its  depth  below 
the  surface. 

9.  Depth  to  ground  water  at  both  house  and  field  where  sewage  is 
to  be  distributed. 

10.  Minimum  winter  temperature  and  approximate  depth  to  which 
frost  goes. 

11.  Number  and  kind  of  buildings  to  be  connected. with  the  sewer. 

12.  Number  and  kind  of  plumbing  fixtures  in  each  building. 

13.  Whether  plumbing  fixtures  are  to  be  put  in  the  basement. 

14.  Depth  of  basement  floor  below  ground. 

A  plan  to  scale  or  a  sketch  with  dimensions  showing  property  lines, 
buildings,  wells,  springs,  and  drainage  outlets  should  be  furnished. 
The  direction  of  surface  drainage  should  be  indicated  by  arrows. 
The  slope  of  the  land  (vertical  fall  in  a  stated  horizontal  distance) 
should  be  given  or  if  possible  a  contour  plan  (showing  lines  of  con- 
stant elevation)  should  be  furnished. 

GREASE  TRAPS. 

Farm  sewage  may  contain  from  10  to  30  pounds  of  grease  and  fats 
per  person  per  year.  This  grease,  originating  mainly  in  the  kitchen 
sink,  hinders  septic  action  and  clogs  pipes,  filters,  and  soils.  Half 
the  grease  may  be  stopped  by  a  septic  tank,  but  the  remainder  goes 
into  the  distribution  system,  interfering  with  its  action.  A  grease 
trap  is  a  device  for  separating  the  grease  from  other  wastes.  The 
need  for  it  may  be  lessened  by  carefully  depositing  waste  greases  and 
fats  with  the  garbage;  but  one  should  always  be  installed  if  the 
kitchen  is  carelessly  managed  or  discharges  quantities  of  greasy 
water  as  at  institutions,  hotels,  boarding  houses,  and  bakeshops. 

A  grease  trap  should  have  several  times  the  capacity  of  the  great- 
est quantity  of  greasy  water  discharged  into  it  at  one  time,  in  order 
that  the  entering  water  shall  be  well  cooled  and  the  grease  congealed. 
The  solidified  grease  rises  to  the  surface  of  the  water  in  the  trap  and 
is  retained  therein.  A  dishpan  of  greasy  water  (2^  to  3  gallons)  is 
the  largest  quantity  likely  to  be  discharged  at  one  time  from  an  ordi- 
nary kitchen  sink,  hence  the  grease  trap  should  have  not  less  capacity 
than  7  or  8  gallons.  Figure  35  shows  three  types  of  grease  traps 
suitable  for  farm  use.  In  each  the  outlet  pipe  has  small  clearance 
at  the  bottom.  This  feature,  together  with  the  V-shaped  hopper  bot- 
tom, tends  to  create  a  scouring  velocity  and  thus  prevent  the  accu- 
mulation of  coffee  grounds  and  other  solid  wastes  in  the  bottom  of  the 
trap.  A  grease  trap  should  be  close  to  the  sink  it  is  intended  to  serve, 
but  not  within  the  kitchen,  on  account  of  objectionable  odors  when 
the  trap  is  opened  to  remove  grease.  It  is  good  practice  to  place  the 
trap  in  the  cellar  or  basement,  where  it  is  safe  from  frost  yet  close 
to  the  source  of  grease. 


54 


Farmers'  Bulletin  1227. 


Sewag 

- 

Do  not  waste  moiu^  ,v  ^feo  _g  .  ^  _/,  after- 

wards seeking  information.  Prepare  a  plan  and  woi*.  -roin  it.  Get 
in  touch  with  your  county  agricultural  and  home  demonstration 
agents.  Advice  may  be  obtained  also  from  extension  workers,  State 
agricultural  colleges,  State  and  local  boards  of  health,  the  United 
States  Public  Health  Service,  and  the  United  States  Department  of 
Agriculture.  Do  not  guess  distances  and  levels.  Use  a  measuring 
tape  and  some  type  of  le^el — engineer's,  architect's,  drainage,  hand, 
or  carpenter's.  Study  this  bulletin,  and  design,  lay  out,  and  construct 
in  accordance  therewith.  Kemember  to :  (1)  Isolate  the  septic  tank — 
\  '••  50  to  100  or  more  feet  from  any  dwelling  and,  if  practicable, 

^eward  of  prevailing  summer  breezes ;  (2)  locate  the  cesspool 
~  or  sewage  distribution  field  downhill  from  the  well  or  spring,  and,  if 
possible,  300  feet  therefrom;  (3)  select  dry,  porous,  deeply  drained 
ground  for  disposal  of  all  sewage ;  (4)  do  not  apply  more  sewage  to  a 
given  area  of  land  than  can  be  thoroughly  absorbed  and  oxidized ;  (5) 
lay  sewers  straight  and  below  the  reach  of  frost,  ventilate  them  thor- 
oughly, and  make  the  joints  water-tight  and  root-proof. 

Makeshift  methods,  materials,  or  devices  should  be  avoided  or  used 
sparingly.  Do  not  place  a  vent  pipe  in  the  top  of  .a  cesspool  or 
septic  tank  if  near  a  dwelling.  Siphon  chamber  and  siphon  may  be 
omitted  in  those  rare  instances  where  it  is  feasible  to  discharge  into 
salt  water  or  into  a  large  stream  already  badly  polluted.  Disposal 
of  sewage  in  a  running  stream  should  be  a  last  resort.  Such  practice 
endangers  water  supplies  downstream,  and  unless  the  volume  and 
velocity  of  flow  are  good  nuisance  may  be  created  in  the  vicinity. 
Do  not  neglect  inspection  and  operation.  Clean  out  settling  tanks 
yearly  or  oftener.  All  pipe  lines  below  ground  should  be  marked 
with  iron  or  stone  markers  to  facilitate  examination,  repair,  or  exten- 
sion of  the  system. 

There  is  a  general  but  erroneous  belief  that  the  cost  of  sewerage 
is  little  in  the  city  but  almost  prohibitive  in  the  country.  All  per- 
.sonal  and  realty  properties  in  one  eastern  city  represent  a  valuation 
of  $10,382  per  home,  which  pays  $355  for  sewers  outside  the  cellar 
wall.  An  average  farm  in  a  Middle  West  State  represents  a  valua- 
tion of  $17,259.  Is  not  the  farmer  justified  in  the  small  outlay  re- 
»•  quired  to  dispose  of  the  farm  sewage?  Because  of  the  issuance  of 
bonds  and  the  apportionment  of  sewer  assessments  for  a  series  of 
years  the  city  dweller  may  have  his  burden  distributed  over  a  long 
period.  The  farmer  does  not  pay  interest  on  these  obligations,  and 
sewer  work  can  be  done  more  cheaply  in  the  country  than  in  the  city. 

Safe  disposal  of  farm  sewage  is  not  a  passing  fad  but  a  vital  neces- 
sity. Besides  being  an  asset  a  good  sewerage  installation  greatly 
promotes  the  wholesomeness  and  healthfulness  of  the  farm.  More- 
over the  benefits  are  far-reaching,  because  farm  products  go  into 
every  home,  and  farm  and  urban  populations  mingle  freely. 


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